import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1251797 - Don't fault struct out of rule tree if all of the potential physical property destinations already have a winning value in the cascade. r=heycam (b64f25ae75)
- Bug 1257688 part 0: Add an "IsLegacyBox" accessor to nsFlexContainerFrame, to enable special handling of display:-webkit-box & display:-webkit-inline-box. r=mats (f728070412)
- Bug 1257688 part 1: Change "-webkit-box-pack" & "-webkit-box-align" to alias their -moz equivalents, & change nsFlexContainerFrame to respect them in a -webkit-box. r=mats (fda7e641bb)
- Bug 1174248 - Apply RTL resizer failure only to GTK2. r=karlt (5f264b52bc)
- Bug 1234941 part 1: Add reftests for "-webkit-box" rendering, with -webkit-box-orient unset. r=heycam (bbdb2737a0)
- Bug 1234941 part 2: Add reftests for "-webkit-box" rendering, with -webkit-box-orient:horizontal. r=heycam (815f24f010)
- Bug 1234941 part 3: Add reftests for "-webkit-box" rendering, with -webkit-box-orient:vertical. r=heycam (a4f71266b9)
- Bug 1257688 part 2: Enable "-webkit-box-pack: justify" sections of -webkit-box reftests, & fix reference cases to use 'space-between' (the modern equivalent). (no review) (7641615ec0)
- Bug 1257688 part 3: Change "-webkit-box-ordinal-group" to alias its -moz equivalent, & change nsFlexContainerFrame to respect it in a -webkit-box. r=mats (90797264fe)
- Bug 1257688 part 4: Add reftests for -webkit-box-ordinal-group inside of display:-webkit-box. r=mats (7623b7a5dd)
- Bug 1257688 part 5: Change "-webkit-box-flex" to alias its -moz equivalent, & change nsFlexContainerFrame to use it instead of flex-shrink & flex-grow in a -webkit-box. r=mats (dabf0415f3)
- Bug 1257688 part 6: Add reftest for -webkit-box-flex inside of display:-webkit-box. r=mats (06d1384d0b)
- Bug 1257688 followup: Fix typo in <title>s in webkit-box-ordinal-group reftests. (no review, test-metadata only) (b8753af073)
- Bug 1262049 part 1: Back out bug 1208344 in its entirety, and mark -webkit-box-orient:vertical reftests as failing (for now). (no review) (fd3890a164)
- Bug 1262049 part 2: Add -webkit-box-orient & -webkit-box-direction as aliases for -moz versions, in the style system (but not yet honored by flexbox layout). r=mats (33e137427f)
- Bug 1262049 part 3: Refactor FlexboxAxisTracker constructor to take pointer to nsFlexContainerFrame. r=mats (0e9a26b85d)
- Bug 1262049 part 4: Refactor some of FlexboxAxisTracker constructor's logic into a helper method. r=mats (c298827ed2)
- Bug 1264837 Part 1 - Remove nsTextBoxFrameSuper. r=dholbert (dc64371da6)
- Bug 1264837 Part 2 - Remove nsColorControlFrameSuper. r=dholbert (166c5c13c3)
- Bug 1264837 Part 3 - Remove nsFormControlFrameSuper. r=dholbert (70c4c13c79)
- Bug 1264837 Part 4 - Remove nsImageControlFrameSuper. r=dholbert (68af4648e6)
- Bug 1264837 Part 5 - Remove nsFlexContainerFrameSuper. r=dholbert (ef7b1a912e)
- Bug 1261553 - Don't return from OnVisibilityChanged implementations without calling the superclass implementation. r=mstange (033d4cdf72)
- Bug 1264837 Part 6 - Remove ImageFrameSuper. r=dholbert (cbf002ba56)
- Bug 1264837 Part 7 - Remove nsInlineFrameBase r=dholbert (42e277593f)
- Bug 1262049 part 5: Honor -webkit-box-orient & -webkit-box-direction when determining axes for a -webkit-box flexbox. r=mats (a4f03722ed)
- Bug 1262049 part 6: Add reftest for -webkit-box-direction. (no review) (d41936d107)
- Bug 1266248 part 1: Rename MapSinglePropertyInto() args, to make src-vs-target distinctions clearer. r=heycam (2d46c21c34)
- Bug 1266248 part 2: Add assertion to verify that MapSinglePropertyInto() isn't called with a logical target-property. r=heycam (c51b780a2b)
- Bug 1264837 Part 8 - Remove nsPluginFrameSuper. r=dholbert (615738f0f0)
- Bug 1264837 Part 9 - Remove nsRubyBaseFrameSuper. r=dholbert (0fb30cf0a3)
- Bug 1264837 Part 10 - Remove nsRubyContentFrameSuper. r=dholbert (df02f9983c)
- Bug 1264837 Part 11 - Remove nsRubyFrameSuper. r=dholbert (684a20009b)
- Bug 1264837 Part 12 - Remove nsRubyTextContainerFrameSuper. r=dholbert (4961565c4b)
- Bug 1264837 Part 13 - Remove nsRubyTextFrameSuper. r=dholbert (aa9e863378)
- bits of  1261230 (cffbacd922)
- Bug 1264837 Part 14 - Remove nsSubDocumentFrameSuper. r=dholbert (2ddc0b2028)
- Bug 1264837 Part 15 - Remove nsVideoFrameBase r=dholbert (c1246fd0bc)
- Bug 1264837 Part 16 - Remove ViewportFrame::Super. r=dholbert (dff457b117)
- Bug 1264837 Part 17 - Remove nsSVGAFrameBase. r=dholbert (0df66e92c5)
- Bug 1253590, part 1 - Generalize AutoReferenceLoopDetector to allow it to be used to limit reference chain lengths. r=longsonr (e1673d2e9e)
- Bug 1253590, part 2 - Use the new AutoReferenceLimiter helper to limit clip path reference chain lengths. r=longsonr (4e03ec9001)
- Bug 1253590, part 3 - Crashtest for long clipPath reference chains. r=longsonr (c4da0e1dc4)
- Bug 1253590, part 4 - Follow-up to return the correct type. r=bustage (61c7fd965a)
- Bug 1264837 Part 18 - Remove nsSVGClipPathFrameBase. r=dholbert (ec78340590)
- Bug 1264837 Part 19 - Remove nsSVGContainerFrameBase. r=dholbert (57c5c44826)
- Bug 1264837 Part 20 - Remove nsSVGFilterFrameBase. r=dholbert (5f41a15a86)
- Bug 1264837 Part 21 - Remove nsSVGForeignObjectFrameBase. r=dholbert (c9aeb556ce)
- Bug 1264837 Part 22 - Remove nsSVGGenericContainerFrameBase. r=dholbert (bd4e21975d)
- Bug 1264837 Part 23 - Remove nsSVGGFrameBase. r=dholbert (bed40424fd)
- Bug 1264837 Part 24 - Remove nsSVGGradientFrameBase. r=dholbert (a9a7d3e0d4)
- Bug 1264837 Part 25 - Remove nsSVGLinearGradientFrameBase. r=dholbert (a48ed6b6b2)
- Bug 1264837 Part 26 - Remove nsSVGRadialGradientFrameBase. r=dholbert (76181ad3b2)
- Bug 1264837 Part 27 - Remove nsSVGImageFrameBase. r=dholbert (5aaa32517d)
- Bug 1242256 - ensure images in patterns and masks animate properly. r=jwatt,seth (cc40ee9520)
- Bug 1264837 Part 28 - Remove nsSVGInnerSVGFrameBase. r=dholbert (04b9d9b5fb)
- Bug 1264837 Part 29 - Remove nsSVGMarkerFrameBase. r=dholbert (bc28eca472)
- Bug 1264837 Part 30 - Remove nsSVGMarkerAnonChildFrameBase. r=dholbert (6898a93a31)
- Bug 1264837 Part 31 - Remove nsSVGMaskFrameBase. r=dholbert (26d0e7a5e1)
- Bug 1264837 Part 32 - Remove nsSVGOuterSVGFrameBase. r=dholbert (a473ae8be3)
- Bug 1264837 Part 33 - Remove nsSVGOuterSVGAnonChildFrameBase. r=dholbert (8c6cca5e9b)
- Bug 1264837 Part 34 - Remove nsSVGPaintServerFrameBase. r=dholbert (eab458bfab)
- Bug 1264837 Part 35 - Remove nsSVGPathGeometryFrameBase. r=dholbert (e5245d2be0)
- Bug 1264837 Part 36 - Remove nsSVGPatternFrameBase. r=dholbert (2df37d4056)
- Bug 1264837 Part 37 - Remove nsSVGStopFrameBase. r=dholbert (e367dba151)
- Bug 1264837 Part 38 - Remove nsSVGSwitchFrameBase. r=dholbert (7ffe7a731a)
- Bug 1264837 Part 39 - Remove nsSVGUseFrameBase. r=dholbert (b4445728e3)
- Bug 1264837 Part 40 - Remove SVGFEContainerFrameBase. r=dholbert (ee08ef9caf)
- Bug 1264837 Part 41 - Remove SVGFEImageFrameBase. r=dholbert (010f79b418)
- Bug 1264837 Part 42 - Remove SVGFELeafFrameBase. r=dholbert (949aeba02d)
- Bug 1264837 Part 44 - Remove SVGTextFrameBase. r=dholbert (bfd0603d44)
- Bug 1264837 Part 45 - Remove SVGViewFrameBase. r=dholbert (151f3c95b2)
- Bug 1265591 patch 1 - Remove Internal/External versions of ReconstructStyleData. r=heycam (a91f96e3b3)
- Bug 1265591 patch 2 - Rename nsIPresShell::ReconstructStyleData to RestyleForCSSRuleChanges. r=heycam (8ad2bc3021)
- Bug 1265591 patch 3 - Make the comment describing RestyleForCSSRuleChanges match reality. r=heycam (2ef053622d)
- Bug 1251150. Add crash annotations if image visibility is re-entering. r=mats (975a3e98d7)
- Bug 1261554 (Part 1) - Prepare for implementing in-displayport visibility tracking. r=mstange (b139489249)
- Bug 1261554 (Part 2) - Mark frames which are added to the display list when painting to the window as having Visibility::IN_DISPLAYPORT. r=mstange (4c8185bf0e)
- Bug 1259529 - Clean up the APZ minimap rendering code a bit. No functional changes. r=BenWa (9b99c27777)
- Bug 1256532 - Show the critical displayport in the APZ minimap as well. r=BenWa (9b131616a0)
- Bug 1251886 - Correct inputFrameID selection when using e10s r=daoshengmu (9e042f6af3)
- Bug 1261554 (Part 3) - Visualize Visibility::IN_DISPLAYPORT regions in the APZ minimap visibility debugger. r=botond (f9b72319e1)
- Bug 1261554 (Followup) - Fix memory reporting for PresShell::mVisibleRegions. r=me (6fc953c1de)
- Bug 1259529 - Ensure that the APZ minimap for subframes remains scaled to the visible portion of the composition bounds. r=BenWa (9f156773cf)
- Bug 1251150. Back out crash annotations used to try to diagnose crash. (db6ba80214)
- missing bits of Bug 1258476 - Optimize CreateRangePaintInfo by generating display lists for the minimum amount of range subtrees rather than for the range common ancestor. r=tn (2ded969082)
- Bug 1237821. Use displayport getter for image visibility in the (unused) display list builder based image visibility code. r=botond (a634182065)
- Bug 1253995 - Display stale image in nsImageFrame if we have a new src but haven't decoded it yet - r=seth (6add357448)
- Bug 1261703. When moving flex frame, position its view as well as any child views. r=dholbert (abd586f55f)
- bug 1246772 - work around x87 floating point truncation issues in gecko r=dholbert (de38865a9f)
- missing bits of 1202908 (4a254234f7)
- Bug 1249134: Remove support for -webkit-appearance as an alias for -moz-appearance, since the two prefixed properties behave differently in practice. r=heycam (7fd6826fb0)
- Bug 1249937 - Rename LayerComposite::SetShadowTransform to SetShadowBaseTransform. r=botond (c91f175b8d)
- Bug 1260335 - On perspective ContainerLayers, the clip deferred from their child layer needs to be affected by the perspective layer's async transforms. r=botond (ee1a19e113)
- Bug 1260335 - Add a comment that explains why the perspective child can't have more than one frame metrics. r=mattwoodrow (639d9ede24)
- Bug 1148978 - Remove plugin window update composition deferment. r=mattwoodrow (01e7da3570)
- Bug 1263515 - Destroy the compositor earlier in RecvWillStop when it still has a valid widget. r=jnicol (c14135bf7c)
- Bug 1258440 - Don't attempt to hide plugin windows when switching trees if the previous remote layer tree didn't contain plugin windows. Fixes a tpaint regression. r=mconley (929db2fdf2)
- Bug 1260976 - Make nsTransitionManager use Keyframe objects to set up transitions; r=heycam (3b8ef91fe9)
- Bug 1265611 - Make TransitionProperty() and ToValue() safe when mProperties is not set; r=heycam (37d234aad4)
- Bug 1259675 - Clean up InternalTransitionEvent r=masayuki (f6526d4dfa)
- Bug 1260976 - Remove some references to properties within nsTransitionManager; r=heycam (6c0f84fb17)
- Bug 1182856 - Part 4: Refactor code in nsTransitionManager::StyleContextChanged(). r=heycam (ee0f4d76fd)
- Bug 1182856 - Part 5: Avoid unnecessary transition update if display:none. r=heycam (5e01fff5cc)
- Bug 1182856 - Part 6: Revise tests for display:none in test_transitions.html. r=heycam (ac2dfe8e47)
- Bug 1182856 - Part 7: Test. r=cam (2aed7d5ae6)
- Bug 1265611 - Don't trigger transitions for properties that are disabled; r=heycam (dabf201421)
- Bug 1247533 - Annotate intentional switch fallthrough to suppress -Wimplicit-fallthrough warning in layout/style/. r=dbaron (a0b748bea2)
- Bug 1264830 - Part 1: Add an nsStyleAutoArray array type, similar to AutoTArray<...,1> but memmovable. r=bholley (ad4eb0692c)
- Bug 1264830 - Part 2: Change nsStyleImageLayers::mLayers to use nsStyleAutoArray. r=bholley (963a9e4033)
- Bug 1264830 - Part 3: Change nsStyleDisplay::{mTransitions,mAnimations} to use nsStyleAutoArray. r=bholley (396812da9d)
- Bug 1264830 - Part 4: Change nsStyleDisplay::mWillChange to use nsTArray. r=bholley (7dead8570f)
- Bug 1264830 - Part 5: Require all style structs be memmovable. r=bholley (8fdd844d1c)
- Bug 1244628: compare nsStyleImageLayers::mAttachmentCount in nsStyleImageLayers::CalcDifference. r=dbaron. (11e2bb1665)
- Bug 1252739 - nsStyleImageLayers::HasLayerWithImage should return true when we have mask-image:<element-reference> | <gradient>; r=dbaron (904b65a0e5)
- cleanup empty line (8263e0793e)
- Bug 1261392 - Define gettid for all Linux builds. r=bgirard (781ae95acc)

browser/app/macbuild/Contents/MacOS-files.in

@@ -7,4 +7,3 @@
 /ssltunnel
 /xpcshell
 /XUL
-

dom/base/nsImageLoadingContent.cpp

@@ -285,9 +285,8 @@ nsImageLoadingContent::OnUnlockedDraw()
     return;
   }
 
-  if (frame->GetVisibility() == Visibility::APPROXIMATELY_VISIBLE) {
+  if (frame->IsVisibleOrMayBecomeVisibleSoon()) {
-    // This frame is already marked visible; there's nothing to do.
+    return;  // Nothing to do.
-    return;
   }
 
   nsPresContext* presContext = frame->PresContext();
@@ -300,7 +299,7 @@ nsImageLoadingContent::OnUnlockedDraw()
     return;
   }
 
-  presShell->EnsureFrameInApproximatelyVisibleList(frame);
+  presShell->MarkFrameVisibleInDisplayPort(frame);
 }
 
 nsresult
@@ -527,7 +526,7 @@ nsImageLoadingContent::FrameDestroyed(nsIFrame* aFrame)
 
   nsIPresShell* presShell = presContext ? presContext->GetPresShell() : nullptr;
   if (presShell) {
-    presShell->RemoveFrameFromApproximatelyVisibleList(aFrame);
+    presShell->MarkFrameNonvisible(aFrame);
   }
 }
 
@@ -1423,12 +1422,13 @@ nsImageLoadingContent::OnVisibilityChange(Visibility aNewVisibility,
                                           const Maybe<OnNonvisible>& aNonvisibleAction)
 {
   switch (aNewVisibility) {
-    case Visibility::APPROXIMATELY_VISIBLE:
+    case Visibility::MAY_BECOME_VISIBLE:
+    case Visibility::IN_DISPLAYPORT:
       TrackImage(mCurrentRequest);
       TrackImage(mPendingRequest);
       break;
 
-    case Visibility::APPROXIMATELY_NONVISIBLE:
+    case Visibility::NONVISIBLE:
       UntrackImage(mCurrentRequest, aNonvisibleAction);
       UntrackImage(mPendingRequest, aNonvisibleAction);
       break;
@@ -1454,11 +1454,11 @@ nsImageLoadingContent::TrackImage(imgIRequest* aImage)
   }
 
   // We only want to track this request if we're visible. Ordinarily we check
-  // the visible count, but that requires a frame; in cases where
+  // whether our frame considers itself visible, but in cases where
   // GetOurPrimaryFrame() cannot obtain a frame (e.g. <feImage>), we assume
   // we're visible if FrameCreated() was called.
   nsIFrame* frame = GetOurPrimaryFrame();
-  if ((frame && frame->GetVisibility() == Visibility::APPROXIMATELY_NONVISIBLE) ||
+  if ((frame && !frame->IsVisibleOrMayBecomeVisibleSoon()) ||
       (!frame && !mFrameCreateCalled)) {
     return;
   }

dom/events/TransitionEvent.cpp

@@ -47,9 +47,9 @@ TransitionEvent::Constructor(const GlobalObject& aGlobal,
   e->InitEvent(aType, aParam.mBubbles, aParam.mCancelable);
 
   InternalTransitionEvent* internalEvent = e->mEvent->AsTransitionEvent();
-  internalEvent->propertyName = aParam.mPropertyName;
+  internalEvent->mPropertyName = aParam.mPropertyName;
-  internalEvent->elapsedTime = aParam.mElapsedTime;
+  internalEvent->mElapsedTime = aParam.mElapsedTime;
-  internalEvent->pseudoElement = aParam.mPseudoElement;
+  internalEvent->mPseudoElement = aParam.mPseudoElement;
 
   e->SetTrusted(trusted);
   return e.forget();
@@ -58,7 +58,7 @@ TransitionEvent::Constructor(const GlobalObject& aGlobal,
 NS_IMETHODIMP
 TransitionEvent::GetPropertyName(nsAString& aPropertyName)
 {
-  aPropertyName = mEvent->AsTransitionEvent()->propertyName;
+  aPropertyName = mEvent->AsTransitionEvent()->mPropertyName;
   return NS_OK;
 }
 
@@ -72,13 +72,13 @@ TransitionEvent::GetElapsedTime(float* aElapsedTime)
 float
 TransitionEvent::ElapsedTime()
 {
-  return mEvent->AsTransitionEvent()->elapsedTime;
+  return mEvent->AsTransitionEvent()->mElapsedTime;
 }
 
 NS_IMETHODIMP
 TransitionEvent::GetPseudoElement(nsAString& aPseudoElement)
 {
-  aPseudoElement = mEvent->AsTransitionEvent()->pseudoElement;
+  aPseudoElement = mEvent->AsTransitionEvent()->mPseudoElement;
   return NS_OK;
 }
 

dom/html/nsHTMLDocument.cpp

@@ -2657,7 +2657,7 @@ nsHTMLDocument::TearingDownEditor(nsIEditor *aEditor)
 
     presShell->SetAgentStyleSheets(agentSheets);
 
-    presShell->ReconstructStyleData();
+    presShell->RestyleForCSSRuleChanges();
   }
 }
 
@@ -2821,7 +2821,7 @@ nsHTMLDocument::EditingStateChanged()
     rv = presShell->SetAgentStyleSheets(agentSheets);
     NS_ENSURE_SUCCESS(rv, rv);
 
-    presShell->ReconstructStyleData();
+    presShell->RestyleForCSSRuleChanges();
 
     // Adjust focused element with new style but blur event shouldn't be fired
     // until mEditingState is modified with newState.

dom/svg/crashtests/crashtests.list

@@ -72,3 +72,5 @@ load 880544-3.svg
 load 880544-4.svg
 load 880544-5.svg
 load 898915-1.svg
+# Disabled for now due to it taking a very long time to run - bug 1259356
+#load long-clipPath-reference-chain.svg

dom/svg/crashtests/long-clipPath-reference-chain.svg

@@ -0,0 +1,53 @@
+<svg xmlns="http://www.w3.org/2000/svg">
+  <title>Test very long clipPath chain - MAY CRASH</title>
+  <script><![CDATA[
+
+// This script creates a very long chain of clipPath elements to test whether
+// that causes a stack overflow that crashes the UA.  The first clipPath clips
+// to a 50x100 rect, the last to a 25x100 rect.  If a UA was to apply the
+// entire clipPath chain (unlikely) a rect 25x100 would be rendered.
+//
+// At the time of writing, Firefox would treat the entire chain of clipPaths as
+// invalid due to its excessive length, and refuse to render the referencing
+// element at all.  One alternative would be to ignore the clipPath reference
+// and render the referencing element without any clipping.  Another
+// alternative would be to break the chain and clip the referencing element,
+// but only using the first X clipPaths in the chain (in which case a 50x100
+// rect would be rendered).
+
+var chainLength = 100000;
+
+var SVG_NS = "http://www.w3.org/2000/svg";
+var template = document.createElementNS(SVG_NS, "clipPath");
+var templatesRect = document.createElementNS(SVG_NS, "rect");
+templatesRect.setAttribute("width", "100");
+templatesRect.setAttribute("height", "100");
+template.appendChild(templatesRect);
+
+function createClipPath(index) {
+  var cp = template.cloneNode(true);
+  cp.id = "c" + index;
+  cp.setAttribute("clip-path", "url(#c" + (index + 1) + ")");
+  return cp;
+}
+
+var de = document.documentElement;
+
+for (var i = chainLength; i > 0; --i) {
+  var cp = createClipPath(i);
+
+  if (i == chainLength) {
+    cp.firstChild.setAttribute("width", "25");
+  }
+  else if (i == 1) {
+    cp.firstChild.setAttribute("width", "50");
+  }
+
+  de.appendChild(cp);
+}
+
+  ]]></script>
+  <rect width="100%" height="100%" fill="lime"/>
+  <!-- We don't expect the following element to render at all -->
+  <rect width="500" height="500" clip-path="url(#c1)"/>
+</svg>

editor/libeditor/nsHTMLEditor.cpp

@@ -2879,7 +2879,7 @@ nsHTMLEditor::AddOverrideStyleSheet(const nsAString& aURL)
   // (This checks if already exists)
   ps->AddOverrideStyleSheet(sheet);
 
-  ps->ReconstructStyleData();
+  ps->RestyleForCSSRuleChanges();
 
   // Save as the last-loaded sheet
   mLastOverrideStyleSheetURL = aURL;
@@ -2924,7 +2924,7 @@ nsHTMLEditor::RemoveOverrideStyleSheet(const nsAString &aURL)
   NS_ENSURE_TRUE(ps, NS_ERROR_NOT_INITIALIZED);
 
   ps->RemoveOverrideStyleSheet(sheet);
-  ps->ReconstructStyleData();
+  ps->RestyleForCSSRuleChanges();
 
   // Remove it from our internal list
   return rv;

gfx/layers/composite/AsyncCompositionManager.cpp

@@ -234,7 +234,7 @@ SetShadowTransform(Layer* aLayer, LayerToParentLayerMatrix4x4 aTransform)
   aTransform.PostScale(1.0f / aLayer->GetPostXScale(),
                        1.0f / aLayer->GetPostYScale(),
                        1);
-  aLayer->AsLayerComposite()->SetShadowTransform(aTransform.ToUnknownMatrix());
+  aLayer->AsLayerComposite()->SetShadowBaseTransform(aTransform.ToUnknownMatrix());
 }
 
 static void
@@ -642,7 +642,7 @@ SampleAnimations(Layer* aLayer, TimeStamp aPoint)
       if (ContainerLayer* c = aLayer->AsContainerLayer()) {
         matrix.PostScale(c->GetInheritedXScale(), c->GetInheritedYScale(), 1);
       }
-      layerComposite->SetShadowTransform(matrix);
+      layerComposite->SetShadowBaseTransform(matrix);
       layerComposite->SetShadowTransformSetByAnimation(true);
       break;
     }
@@ -811,6 +811,11 @@ AsyncCompositionManager::ApplyAsyncContentTransformToTree(Layer *aLayer,
   // The final clip for the layer is the intersection of these clips.
   Maybe<ParentLayerIntRect> asyncClip = aLayer->GetClipRect();
 
+  // If we are a perspective transform ContainerLayer, apply the clip deferred
+  // from our child (if there is any) before we iterate over our frame metrics,
+  // because this clip is subject to all async transforms of this layer.
+  asyncClip = IntersectMaybeRects(asyncClip, clipDeferredFromChildren);
+
   // The transform of a mask layer is relative to the masked layer's parent
   // layer. So whenever we apply an async transform to a layer, we need to
   // apply that same transform to the layer's own mask layer.
@@ -934,6 +939,12 @@ AsyncCompositionManager::ApplyAsyncContentTransformToTree(Layer *aLayer,
         // our scroll clip to it instead of to this layer (see bug 1168263).
         // A layer with a perspective transform shouldn't have multiple
         // children with FrameMetrics, nor a child with multiple FrameMetrics.
+        // (A child with multiple FrameMetrics would mean that there's *another*
+        // scrollable element between the one with the CSS perspective and the
+        // transformed element. But you'd have to use preserve-3d on the inner
+        // scrollable element in order to have the perspective apply to the
+        // transformed child, and preserve-3d is not supported on scrollable
+        // elements, so this case can't occur.)
         MOZ_ASSERT(!aClipDeferredToParent);
         aClipDeferredToParent = Some(clip);
       } else {
@@ -958,8 +969,7 @@ AsyncCompositionManager::ApplyAsyncContentTransformToTree(Layer *aLayer,
   }
 
   if (hasAsyncTransform || clipDeferredFromChildren) {
-    aLayer->AsLayerComposite()->SetShadowClipRect(
+    aLayer->AsLayerComposite()->SetShadowClipRect(asyncClip);
-        IntersectMaybeRects(asyncClip, clipDeferredFromChildren));
   }
 
   if (hasAsyncTransform) {
@@ -1426,7 +1436,7 @@ AsyncCompositionManager::TransformShadowTree(TimeStamp aCurrentFrame,
 
   gfx::Matrix4x4 trans = rootComposite->GetShadowBaseTransform();
   trans *= gfx::Matrix4x4::From2D(mWorldTransform);
-  rootComposite->SetShadowTransform(trans);
+  rootComposite->SetShadowBaseTransform(trans);
 
   if (gfxPrefs::CollectScrollTransforms()) {
     RecordShadowTransforms(root);

gfx/layers/composite/ContainerLayerComposite.cpp

@@ -141,8 +141,7 @@ template<class ContainerT> void
 ContainerRenderVR(ContainerT* aContainer,
                   LayerManagerComposite* aManager,
                   const gfx::IntRect& aClipRect,
-                  RefPtr<gfx::VRHMDInfo> aHMD,
+                  RefPtr<gfx::VRHMDInfo> aHMD)
-                  int32_t aInputFrameID)
 {
   int32_t inputFrameID = -1;
 
@@ -273,11 +272,29 @@ ContainerRenderVR(ContainerT* aContainer,
                                                  surfaceRect.width, surfaceRect.height));
       layerToRender->RenderLayer(surfaceRect);
 
-      CompositableHost *ch = layerToRender->GetCompositableHost();
+      // Search all children recursively until we find the canvas with
-      if (ch) {
+      // an inputFrameID
-        int32_t compositableInputFrameID = ch->GetLastInputFrameID();
+      std::stack<LayerComposite*> searchLayers;
-        if (compositableInputFrameID != -1) {
+      searchLayers.push(layerToRender);
-          inputFrameID = compositableInputFrameID;
+      while (!searchLayers.empty() && inputFrameID == -1) {
+        LayerComposite* searchLayer = searchLayers.top();
+        searchLayers.pop();
+        if (searchLayer) {
+          searchLayers.push(searchLayer->GetFirstChildComposite());
+          Layer* sibling = searchLayer->GetLayer();
+          if (sibling) {
+            sibling = sibling->GetNextSibling();
+          }
+          if (sibling) {
+            searchLayers.push(sibling->AsLayerComposite());
+          }
+          CompositableHost *ch = searchLayer->GetCompositableHost();
+          if (ch) {
+            int32_t compositableInputFrameID = ch->GetLastInputFrameID();
+            if (compositableInputFrameID != -1) {
+              inputFrameID = compositableInputFrameID;
+            }
+          }
         }
       }
 
@@ -457,6 +474,22 @@ ContainerPrepare(ContainerT* aContainer,
   }
 }
 
+template <typename RectPainter> void
+DrawRegion(CSSIntRegion* aRegion,
+           gfx::Color aColor,
+           const RectPainter& aRectPainter)
+{
+  MOZ_ASSERT(aRegion);
+
+  // Iterate through and draw the rects in the region using the provided lambda.
+  for (CSSIntRegion::RectIterator iterator = aRegion->RectIter();
+       !iterator.Done();
+       iterator.Next())
+  {
+    aRectPainter(iterator.Get(), aColor);
+  }
+}
+
 template<class ContainerT> void
 RenderMinimap(ContainerT* aContainer, LayerManagerComposite* aManager,
                    const RenderTargetIntRect& aClipRect, Layer* aLayer)
@@ -481,9 +514,11 @@ RenderMinimap(ContainerT* aContainer, LayerManagerComposite* aManager,
   gfx::Color tileActiveColor(1, 1, 1, 0.4f);
   gfx::Color tileBorderColor(0, 0, 0, 0.1f);
   gfx::Color pageBorderColor(0, 0, 0);
+  gfx::Color criticalDisplayPortColor(1.f, 1.f, 0);
   gfx::Color displayPortColor(0, 1.f, 0);
   gfx::Color viewPortColor(0, 0, 1.f, 0.3f);
-  gfx::Color visibilityColor(1.f, 0, 0);
+  gfx::Color approxVisibilityColor(1.f, 0, 0);
+  gfx::Color inDisplayPortVisibilityColor(1.f, 1.f, 0);
 
   // Rects
   const FrameMetrics& fm = aLayer->GetFrameMetrics(0);
@@ -491,6 +526,10 @@ RenderMinimap(ContainerT* aContainer, LayerManagerComposite* aManager,
   LayerRect scrollRect = fm.GetScrollableRect() * fm.LayersPixelsPerCSSPixel();
   LayerRect viewRect = ParentLayerRect(scrollOffset, compositionBounds.Size()) / LayerToParentLayerScale(1);
   LayerRect dp = (fm.GetDisplayPort() + fm.GetScrollOffset()) * fm.LayersPixelsPerCSSPixel();
+  Maybe<LayerRect> cdp;
+  if (!fm.GetCriticalDisplayPort().IsEmpty()) {
+    cdp = Some((fm.GetCriticalDisplayPort() + fm.GetScrollOffset()) * fm.LayersPixelsPerCSSPixel());
+  }
 
   // Don't render trivial minimap. They can show up from textboxes and other tiny frames.
   if (viewRect.width < 64 && viewRect.height < 64) {
@@ -502,41 +541,32 @@ RenderMinimap(ContainerT* aContainer, LayerManagerComposite* aManager,
   float scaleFactor;
   float scaleFactorX;
   float scaleFactorY;
-  scaleFactorX = 100.f / scrollRect.width;
+  Rect dest = Rect(aClipRect.ToUnknownRect());
-  scaleFactorY = ((viewRect.height) - 2 * verticalPadding) / scrollRect.height;
+  if (aLayer->GetEffectiveClipRect()) {
+    dest = Rect(aLayer->GetEffectiveClipRect().value().ToUnknownRect());
+  } else {
+    dest = aContainer->GetEffectiveTransform().Inverse().TransformBounds(dest);
+  }
+  dest = dest.Intersect(compositionBounds.ToUnknownRect());
+  scaleFactorX = std::min(100.f, dest.width - (2 * horizontalPadding)) / scrollRect.width;
+  scaleFactorY = (dest.height - (2 * verticalPadding)) / scrollRect.height;
   scaleFactor = std::min(scaleFactorX, scaleFactorY);
+  if (scaleFactor <= 0) {
+    return;
+  }
 
   Matrix4x4 transform = Matrix4x4::Scaling(scaleFactor, scaleFactor, 1);
-  transform.PostTranslate(horizontalPadding + compositionBounds.x, verticalPadding + compositionBounds.y, 0);
+  transform.PostTranslate(horizontalPadding + dest.x, verticalPadding + dest.y, 0);
 
-  Rect clipRect = aContainer->GetEffectiveTransform().TransformBounds(
+  Rect transformedScrollRect = transform.TransformBounds(scrollRect.ToUnknownRect());
-                    transform.TransformBounds(scrollRect.ToUnknownRect()));
+
+  Rect clipRect = aContainer->GetEffectiveTransform().TransformBounds(transformedScrollRect);
   clipRect.width++;
   clipRect.height++;
 
-  Rect r;
-  r = transform.TransformBounds(scrollRect.ToUnknownRect());
-  compositor->FillRect(r, backgroundColor, clipRect, aContainer->GetEffectiveTransform());
-
-  /* Disabled because on long pages SlowDrawRect becomes a bottleneck.
-  int tileW = gfxPrefs::LayersTileWidth();
-  int tileH = gfxPrefs::LayersTileHeight();
-
-  for (int x = scrollRect.x; x < scrollRect.XMost(); x += tileW) {
-    for (int y = scrollRect.y; y < scrollRect.YMost(); y += tileH) {
-      LayerRect tileRect = LayerRect(x - x % tileW, y - y % tileH, tileW, tileH);
-      r = transform.TransformBounds(tileRect.ToUnknownRect());
-      if (tileRect.Intersects(dp)) {
-        compositor->FillRect(r, tileActiveColor, clipRect, aContainer->GetEffectiveTransform());
-      }
-      compositor->SlowDrawRect(r, tileBorderColor, clipRect, aContainer->GetEffectiveTransform());
-    }
-  }
-  */
-
   // Render the scrollable area.
-  r = transform.TransformBounds(scrollRect.ToUnknownRect());
+  compositor->FillRect(transformedScrollRect, backgroundColor, clipRect, aContainer->GetEffectiveTransform());
-  compositor->SlowDrawRect(r, pageBorderColor, clipRect, aContainer->GetEffectiveTransform());
+  compositor->SlowDrawRect(transformedScrollRect, pageBorderColor, clipRect, aContainer->GetEffectiveTransform());
 
   // If enabled, render information about visibility.
   if (gfxPrefs::APZMinimapVisibilityEnabled()) {
@@ -547,31 +577,34 @@ RenderMinimap(ContainerT* aContainer, LayerManagerComposite* aManager,
 
     ScrollableLayerGuid guid = controller->GetGuid();
 
-    // Get the approximately visible region.
+    auto rectPainter = [&](const CSSIntRect& aRect, const gfx::Color& aColor) {
-    static CSSIntRegion emptyRegion;
+      LayerRect scaledRect = aRect * fm.LayersPixelsPerCSSPixel();
-    CSSIntRegion* visibleRegion = aManager->GetApproximatelyVisibleRegion(guid);
-    if (!visibleRegion) {
-      visibleRegion = &emptyRegion;
-    }
-
-    // Iterate through and draw the rects in the region.
-    for (CSSIntRegion::RectIterator iterator = visibleRegion->RectIter();
-         !iterator.Done();
-         iterator.Next())
-    {
-      CSSIntRect rect = iterator.Get();
-      LayerRect scaledRect = rect * fm.LayersPixelsPerCSSPixel();
       Rect r = transform.TransformBounds(scaledRect.ToUnknownRect());
-      compositor->FillRect(r, visibilityColor, clipRect, aContainer->GetEffectiveTransform());
+      compositor->FillRect(r, aColor, clipRect, aContainer->GetEffectiveTransform());
-    }
+    };
+
+    // Draw the approximately visible region.
+    CSSIntRegion* approxVisibleRegion =
+      aManager->GetVisibleRegion(VisibilityCounter::MAY_BECOME_VISIBLE, guid);
+    DrawRegion(approxVisibleRegion, approxVisibilityColor, rectPainter);
+
+    // Draw the in-displayport visible region.
+    CSSIntRegion* inDisplayPortVisibleRegion =
+      aManager->GetVisibleRegion(VisibilityCounter::IN_DISPLAYPORT, guid);
+    DrawRegion(inDisplayPortVisibleRegion, inDisplayPortVisibilityColor, rectPainter);
   }
 
   // Render the displayport.
-  r = transform.TransformBounds(dp.ToUnknownRect());
+  Rect r = transform.TransformBounds(dp.ToUnknownRect());
   compositor->FillRect(r, tileActiveColor, clipRect, aContainer->GetEffectiveTransform());
-  r = transform.TransformBounds(dp.ToUnknownRect());
   compositor->SlowDrawRect(r, displayPortColor, clipRect, aContainer->GetEffectiveTransform());
 
+  // Render the critical displayport if there is one
+  if (cdp) {
+    r = transform.TransformBounds(cdp->ToUnknownRect());
+    compositor->SlowDrawRect(r, criticalDisplayPortColor, clipRect, aContainer->GetEffectiveTransform());
+  }
+
   // Render the viewport.
   r = transform.TransformBounds(viewRect.ToUnknownRect());
   compositor->SlowDrawRect(r, viewPortColor, clipRect, aContainer->GetEffectiveTransform(), 2);
@@ -750,7 +783,7 @@ ContainerRender(ContainerT* aContainer,
 
   RefPtr<gfx::VRHMDInfo> hmdInfo = gfx::VRManager::Get()->GetDevice(aContainer->GetVRDeviceID());
   if (hmdInfo && hmdInfo->GetConfiguration().IsValid()) {
-    ContainerRenderVR(aContainer, aManager, aClipRect, hmdInfo, aContainer->GetInputFrameID());
+    ContainerRenderVR(aContainer, aManager, aClipRect, hmdInfo);
     aContainer->mPrepared = nullptr;
     return;
   }

gfx/layers/composite/LayerManagerComposite.h

@@ -33,6 +33,7 @@
 #include "nsRegion.h"                   // for nsIntRegion
 #include "nscore.h"                     // for nsAString, etc
 #include "LayerTreeInvalidation.h"
+#include "Visibility.h"
 
 class gfxContext;
 
@@ -219,10 +220,17 @@ public:
     mInvalidRegion.Or(mInvalidRegion, aRegion);
   }
 
-  void ClearApproximatelyVisibleRegions(uint64_t aLayersId,
+  void ClearVisibleRegions(uint64_t aLayersId,
-                                        const Maybe<uint32_t>& aPresShellId)
+                           const Maybe<uint32_t>& aPresShellId)
   {
-    for (auto iter = mVisibleRegions.Iter(); !iter.Done(); iter.Next()) {
+    for (auto iter = mApproximatelyVisibleRegions.Iter(); !iter.Done(); iter.Next()) {
+      if (iter.Key().mLayersId == aLayersId &&
+          (!aPresShellId || iter.Key().mPresShellId == *aPresShellId)) {
+        iter.Remove();
+      }
+    }
+
+    for (auto iter = mInDisplayPortVisibleRegions.Iter(); !iter.Done(); iter.Next()) {
       if (iter.Key().mLayersId == aLayersId &&
           (!aPresShellId || iter.Key().mPresShellId == *aPresShellId)) {
         iter.Remove();
@@ -230,18 +238,35 @@ public:
     }
   }
 
-  void UpdateApproximatelyVisibleRegion(const ScrollableLayerGuid& aGuid,
+  void UpdateVisibleRegion(VisibilityCounter aCounter,
-                                        const CSSIntRegion& aRegion)
+                           const ScrollableLayerGuid& aGuid,
+                           const CSSIntRegion& aRegion)
   {
-    CSSIntRegion* regionForScrollFrame = mVisibleRegions.LookupOrAdd(aGuid);
+    VisibleRegions& regions = aCounter == VisibilityCounter::MAY_BECOME_VISIBLE
+                            ? mApproximatelyVisibleRegions
+                            : mInDisplayPortVisibleRegions;
+
+    CSSIntRegion* regionForScrollFrame = regions.LookupOrAdd(aGuid);
     MOZ_ASSERT(regionForScrollFrame);
 
     *regionForScrollFrame = aRegion;
   }
 
-  CSSIntRegion* GetApproximatelyVisibleRegion(const ScrollableLayerGuid& aGuid)
+  CSSIntRegion* GetVisibleRegion(VisibilityCounter aCounter,
+                                 const ScrollableLayerGuid& aGuid)
   {
-    return mVisibleRegions.Get(aGuid);
+    static CSSIntRegion emptyRegion;
+
+    VisibleRegions& regions = aCounter == VisibilityCounter::MAY_BECOME_VISIBLE
+                            ? mApproximatelyVisibleRegions
+                            : mInDisplayPortVisibleRegions;
+
+    CSSIntRegion* region = regions.Get(aGuid);
+    if (!region) {
+      region = &emptyRegion;
+    }
+
+    return region;
   }
 
   Compositor* GetCompositor() const
@@ -382,7 +407,8 @@ private:
 
   typedef nsClassHashtable<nsGenericHashKey<ScrollableLayerGuid>,
                            CSSIntRegion> VisibleRegions;
-  VisibleRegions mVisibleRegions;
+  VisibleRegions mApproximatelyVisibleRegions;
+  VisibleRegions mInDisplayPortVisibleRegions;
 
   UniquePtr<FPSState> mFPS;
 
@@ -491,7 +517,7 @@ public:
     mShadowClipRect = aRect;
   }
 
-  void SetShadowTransform(const gfx::Matrix4x4& aMatrix)
+  void SetShadowBaseTransform(const gfx::Matrix4x4& aMatrix)
   {
     mShadowTransform = aMatrix;
   }

gfx/layers/ipc/CompositorBridgeChild.cpp

@@ -727,29 +727,28 @@ CompositorBridgeChild::SendRequestNotifyAfterRemotePaint()
 }
 
 bool
-CompositorBridgeChild::SendClearApproximatelyVisibleRegions(uint64_t aLayersId,
+CompositorBridgeChild::SendClearVisibleRegions(uint64_t aLayersId,
-                                                            uint32_t aPresShellId)
+                                               uint32_t aPresShellId)
 {
   MOZ_ASSERT(mCanSend);
   if (!mCanSend) {
     return true;
   }
-  return PCompositorBridgeChild::SendClearApproximatelyVisibleRegions(aLayersId,
+  return PCompositorBridgeChild::SendClearVisibleRegions(aLayersId, aPresShellId);
-                                                                aPresShellId);
 }
 
 bool
-CompositorBridgeChild::SendNotifyApproximatelyVisibleRegion(const ScrollableLayerGuid& aGuid,
+CompositorBridgeChild::SendUpdateVisibleRegion(VisibilityCounter aCounter,
-                                                            const CSSIntRegion& aRegion)
+                                               const ScrollableLayerGuid& aGuid,
+                                               const CSSIntRegion& aRegion)
 {
   MOZ_ASSERT(mCanSend);
   if (!mCanSend) {
     return true;
   }
-  return PCompositorBridgeChild::SendNotifyApproximatelyVisibleRegion(aGuid, aRegion);
+  return PCompositorBridgeChild::SendUpdateVisibleRegion(aCounter, aGuid, aRegion);
 }
 
-
 } // namespace layers
 } // namespace mozilla
 

gfx/layers/ipc/CompositorBridgeChild.h

@@ -126,9 +126,10 @@ public:
   bool SendStopFrameTimeRecording(const uint32_t& startIndex, nsTArray<float>* intervals);
   bool SendNotifyRegionInvalidated(const nsIntRegion& region);
   bool SendRequestNotifyAfterRemotePaint();
-  bool SendClearApproximatelyVisibleRegions(uint64_t aLayersId, uint32_t aPresShellId);
+  bool SendClearVisibleRegions(uint64_t aLayersId, uint32_t aPresShellId);
-  bool SendNotifyApproximatelyVisibleRegion(const ScrollableLayerGuid& aGuid,
+  bool SendUpdateVisibleRegion(VisibilityCounter aCounter,
-                                            const mozilla::CSSIntRegion& aRegion);
+                               const ScrollableLayerGuid& aGuid,
+                               const mozilla::CSSIntRegion& aRegion);
   bool IsSameProcess() const;
 
   static void ShutDown();

gfx/layers/ipc/CompositorBridgeParent.cpp

@@ -701,7 +701,6 @@ CompositorBridgeParent::CompositorBridgeParent(nsIWidget* aWidget,
   , mCompositorScheduler(nullptr)
 #if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
   , mLastPluginUpdateLayerTreeId(0)
-  , mPluginUpdateResponsePending(false)
   , mDeferPluginWindows(false)
   , mPluginWindowsHidden(false)
 #endif
@@ -785,6 +784,8 @@ CompositorBridgeParent::RecvWillClose()
 
   if (mCompositor) {
     mCompositor->DetachWidget();
+    mCompositor->Destroy();
+    mCompositor = nullptr;
   }
 
   return true;
@@ -897,19 +898,19 @@ CompositorBridgeParent::RecvStopFrameTimeRecording(const uint32_t& aStartIndex,
 }
 
 bool
-CompositorBridgeParent::RecvClearApproximatelyVisibleRegions(const uint64_t& aLayersId,
+CompositorBridgeParent::RecvClearVisibleRegions(const uint64_t& aLayersId,
-                                                            const uint32_t& aPresShellId)
+                                                const uint32_t& aPresShellId)
 {
-  ClearApproximatelyVisibleRegions(aLayersId, Some(aPresShellId));
+  ClearVisibleRegions(aLayersId, Some(aPresShellId));
   return true;
 }
 
 void
-CompositorBridgeParent::ClearApproximatelyVisibleRegions(const uint64_t& aLayersId,
+CompositorBridgeParent::ClearVisibleRegions(const uint64_t& aLayersId,
-                                                         const Maybe<uint32_t>& aPresShellId)
+                                            const Maybe<uint32_t>& aPresShellId)
 {
   if (mLayerManager) {
-    mLayerManager->ClearApproximatelyVisibleRegions(aLayersId, aPresShellId);
+    mLayerManager->ClearVisibleRegions(aLayersId, aPresShellId);
 
     // We need to recomposite to update the minimap.
     ScheduleComposition();
@@ -917,16 +918,25 @@ CompositorBridgeParent::ClearApproximatelyVisibleRegions(const uint64_t& aLayers
 }
 
 bool
-CompositorBridgeParent::RecvNotifyApproximatelyVisibleRegion(const ScrollableLayerGuid& aGuid,
+CompositorBridgeParent::RecvUpdateVisibleRegion(const VisibilityCounter& aCounter,
-                                                             const CSSIntRegion& aRegion)
+                                                const ScrollableLayerGuid& aGuid,
+                                                const CSSIntRegion& aRegion)
+{
+  UpdateVisibleRegion(aCounter, aGuid, aRegion);
+  return true;
+}
+
+void
+CompositorBridgeParent::UpdateVisibleRegion(const VisibilityCounter& aCounter,
+                                            const ScrollableLayerGuid& aGuid,
+                                            const CSSIntRegion& aRegion)
 {
   if (mLayerManager) {
-    mLayerManager->UpdateApproximatelyVisibleRegion(aGuid, aRegion);
+    mLayerManager->UpdateVisibleRegion(aCounter, aGuid, aRegion);
 
     // We need to recomposite to update the minimap.
     ScheduleComposition();
   }
-  return true;
 }
 
 void
@@ -1175,7 +1185,7 @@ CompositorBridgeParent::SetShadowProperties(Layer* aLayer)
   // FIXME: Bug 717688 -- Do these updates in LayerTransactionParent::RecvUpdate.
   LayerComposite* layerComposite = aLayer->AsLayerComposite();
   // Set the layerComposite's base transform to the layer's base transform.
-  layerComposite->SetShadowTransform(aLayer->GetBaseTransform());
+  layerComposite->SetShadowBaseTransform(aLayer->GetBaseTransform());
   layerComposite->SetShadowTransformSetByAnimation(false);
   layerComposite->SetShadowVisibleRegion(aLayer->GetVisibleRegion());
   layerComposite->SetShadowClipRect(aLayer->GetClipRect());
@@ -1213,20 +1223,6 @@ CompositorBridgeParent::CompositeToTarget(DrawTarget* aTarget, const gfx::IntRec
     return;
   }
 
-#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
-  // Still waiting on plugin update confirmation
-  if (mPluginUpdateResponsePending) {
-    return;
-  }
-#endif
-
-  bool hasRemoteContent = false;
-  bool pluginsUpdatedFlag = true;
-  AutoResolveRefLayers resolve(mCompositionManager, this,
-                               &hasRemoteContent,
-                               &pluginsUpdatedFlag);
-
-#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
   /*
    * AutoResolveRefLayers handles two tasks related to Windows and Linux
    * plugin window management:
@@ -1239,27 +1235,20 @@ CompositorBridgeParent::CompositeToTarget(DrawTarget* aTarget, const gfx::IntRec
    * since plugin clipping can depend on chrome (for example, due to tab modal
    * prompts). Updates in step 2 are applied via an async ipc message sent
    * to the main thread.
-   * Windows specific: The compositor will wait for confirmation that plugin
-   * updates have been applied before painting. Deferment of painting is
-   * indicated by the mPluginUpdateResponsePending flag. The main thread
-   * messages back using the RemotePluginsReady async ipc message.
-   * This is neccessary since plugin windows can leave remnants of window
-   * content if moved after the underlying window paints.
    */
-  if (pluginsUpdatedFlag) {
+  bool hasRemoteContent = false;
-    mPluginUpdateResponsePending = true;
+  bool updatePluginsFlag = true;
-    return;
+  AutoResolveRefLayers resolve(mCompositionManager, this,
-  }
+                               &hasRemoteContent,
+                               &updatePluginsFlag);
 
+#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
   // We do not support plugins in local content. When switching tabs
   // to local pages, hide every plugin associated with the window.
   if (!hasRemoteContent && BrowserTabsRemoteAutostart() &&
       mCachedPluginData.Length()) {
     Unused << SendHideAllPlugins((uintptr_t)GetWidget());
     mCachedPluginData.Clear();
-    // Wait for confirmation the hide operation is complete.
-    mPluginUpdateResponsePending = true;
-    return;
   }
 #endif
 
@@ -1343,7 +1332,6 @@ bool
 CompositorBridgeParent::RecvRemotePluginsReady()
 {
 #if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
-  mPluginUpdateResponsePending = false;
   ScheduleComposition();
   return true;
 #else
@@ -1770,7 +1758,7 @@ EraseLayerState(uint64_t aId)
   if (iter != sIndirectLayerTrees.end()) {
     CompositorBridgeParent* parent = iter->second.mParent;
     if (parent) {
-      parent->ClearApproximatelyVisibleRegions(aId, Nothing());
+      parent->ClearVisibleRegions(aId, Nothing());
     }
 
     sIndirectLayerTrees.erase(iter);
@@ -1953,31 +1941,38 @@ public:
   virtual bool RecvStartFrameTimeRecording(const int32_t& aBufferSize, uint32_t* aOutStartIndex) override { return true; }
   virtual bool RecvStopFrameTimeRecording(const uint32_t& aStartIndex, InfallibleTArray<float>* intervals) override  { return true; }
 
-  virtual bool RecvClearApproximatelyVisibleRegions(const uint64_t& aLayersId,
+  virtual bool RecvClearVisibleRegions(const uint64_t& aLayersId,
-                                                    const uint32_t& aPresShellId) override
+                                       const uint32_t& aPresShellId) override
   {
     CompositorBridgeParent* parent;
     { // scope lock
       MonitorAutoLock lock(*sIndirectLayerTreesLock);
       parent = sIndirectLayerTrees[aLayersId].mParent;
     }
-    if (parent) {
+
-      parent->ClearApproximatelyVisibleRegions(aLayersId, Some(aPresShellId));
+    if (!parent) {
+      return false;
     }
+
+    parent->ClearVisibleRegions(aLayersId, Some(aPresShellId));
     return true;
   }
 
-  virtual bool RecvNotifyApproximatelyVisibleRegion(const ScrollableLayerGuid& aGuid,
+  virtual bool RecvUpdateVisibleRegion(const VisibilityCounter& aCounter,
-                                                    const CSSIntRegion& aRegion) override
+                                       const ScrollableLayerGuid& aGuid,
+                                       const CSSIntRegion& aRegion) override
   {
     CompositorBridgeParent* parent;
     { // scope lock
       MonitorAutoLock lock(*sIndirectLayerTreesLock);
       parent = sIndirectLayerTrees[aGuid.mLayersId].mParent;
     }
-    if (parent) {
+
-      return parent->RecvNotifyApproximatelyVisibleRegion(aGuid, aRegion);
+    if (!parent) {
+      return false;
     }
+
+    parent->UpdateVisibleRegion(aCounter, aGuid, aRegion);
     return true;
   }
 
@@ -2474,6 +2469,11 @@ CompositorBridgeParent::UpdatePluginWindowState(uint64_t aId)
   }
 
   if (!lts.mPluginData.Length()) {
+    // Don't hide plugins if the previous remote layer tree didn't contain any.
+    if (!mCachedPluginData.Length()) {
+      PLUGINS_LOG("[%" PRIu64 "] nothing to hide", aId);
+      return false;
+    }
     // We will pass through here in cases where the previous shadow layer
     // tree contained visible plugins and the new tree does not. All we need
     // to do here is hide the plugins for the old tree, so don't waste time
@@ -2562,7 +2562,6 @@ CompositorBridgeParent::HideAllPluginWindows()
     return;
   }
   mDeferPluginWindows = true;
-  mPluginUpdateResponsePending = true;
   mPluginWindowsHidden = true;
   Unused << SendHideAllPlugins((uintptr_t)GetWidget());
   ScheduleComposition();

gfx/layers/ipc/CompositorBridgeParent.h

@@ -258,12 +258,16 @@ public:
   // @see CrossProcessCompositorBridgeParent::RecvRequestNotifyAfterRemotePaint
   virtual bool RecvRequestNotifyAfterRemotePaint() override { return true; };
 
-  virtual bool RecvClearApproximatelyVisibleRegions(const uint64_t& aLayersId,
+  virtual bool RecvClearVisibleRegions(const uint64_t& aLayersId,
-                                                    const uint32_t& aPresShellId) override;
+                                       const uint32_t& aPresShellId) override;
-  void ClearApproximatelyVisibleRegions(const uint64_t& aLayersId,
+  void ClearVisibleRegions(const uint64_t& aLayersId,
-                                        const Maybe<uint32_t>& aPresShellId);
+                           const Maybe<uint32_t>& aPresShellId);
-  virtual bool RecvNotifyApproximatelyVisibleRegion(const ScrollableLayerGuid& aGuid,
+  virtual bool RecvUpdateVisibleRegion(const VisibilityCounter& aCounter,
-                                                    const CSSIntRegion& aRegion) override;
+                                       const ScrollableLayerGuid& aGuid,
+                                       const CSSIntRegion& aRegion) override;
+  void UpdateVisibleRegion(const VisibilityCounter& aCounter,
+                           const ScrollableLayerGuid& aGuid,
+                           const CSSIntRegion& aRegion);
 
   virtual void ActorDestroy(ActorDestroyReason why) override;
 
@@ -599,9 +603,6 @@ protected:
   nsIntPoint mPluginsLayerOffset;
   nsIntRegion mPluginsLayerVisibleRegion;
   nsTArray<PluginWindowData> mCachedPluginData;
-  // indicates if we are currently waiting on a plugin update confirmation.
-  // When this is true, composition is currently on hold.
-  bool mPluginUpdateResponsePending;
   // indicates if plugin window visibility and metric updates are currently
   // being defered due to a scroll operation.
   bool mDeferPluginWindows;

gfx/layers/ipc/PCompositorBridge.ipdl

@@ -25,6 +25,7 @@ using mozilla::ipc::SharedMemoryBasic::Handle from "mozilla/ipc/SharedMemoryBasi
 using mozilla::CSSIntRegion from "Units.h";
 using mozilla::LayoutDeviceIntPoint from "Units.h";
 using mozilla::LayoutDeviceIntRegion from "Units.h";
+using mozilla::VisibilityCounter from "VisibilityIPC.h";
 using class mozilla::TimeStamp from "mozilla/TimeStamp.h";
 using class mozilla::layers::FrameUniformityData from "mozilla/layers/FrameUniformityData.h";
 
@@ -173,15 +174,18 @@ parent:
    */
   async RequestNotifyAfterRemotePaint();
 
-  // The child clears the 'approximately visible' regions associated with the
+  // The child sends a request to clear the visible regions (approximate,
-  // provided layers ID and pres shell ID (i.e., the regions for all view IDs
+  // in-displayport, etc.) associated with the provided layers ID and pres shell
-  // associated with those IDs).
+  // ID (i.e., the regions for all view IDs associated with those IDs).
-  async ClearApproximatelyVisibleRegions(uint64_t layersId, uint32_t presShellId);
+  async ClearVisibleRegions(uint64_t layersId, uint32_t presShellId);
 
   // The child sends a region containing rects associated with the provided
-  // scrollable layer GUID that the child considers 'approximately visible'.
+  // scrollable layer GUID that the child considers visible in the sense
+  // specified by |counter|.
   // We visualize this information in the APZ minimap.
-  async NotifyApproximatelyVisibleRegion(ScrollableLayerGuid guid, CSSIntRegion region);
+  async UpdateVisibleRegion(VisibilityCounter counter,
+                            ScrollableLayerGuid guid,
+                            CSSIntRegion region);
 
 child:
   // Send back Compositor Frame Metrics from APZCs so tiled layers can

gfx/vr/gfxVROculus.cpp

@@ -526,6 +526,12 @@ HMDInfoOculus::SubmitFrame(RenderTargetSet *aRTSet, int32_t aInputFrameID)
   RenderTargetSetOculus *rts = static_cast<RenderTargetSetOculus*>(aRTSet);
   MOZ_ASSERT(rts->hmd != nullptr);
   MOZ_ASSERT(rts->textureSet != nullptr);
+  MOZ_ASSERT(aInputFrameID >= 0);
+  if (aInputFrameID < 0) {
+    // Sanity check to prevent invalid memory access on builds with assertions
+    // disabled.
+    aInputFrameID = 0;
+  }
 
   VRHMDSensorState sensorState = mLastSensorState[aInputFrameID % kMaxLatencyFrames];
   // It is possible to get a cache miss on mLastSensorState if latency is
@@ -535,6 +541,7 @@ HMDInfoOculus::SubmitFrame(RenderTargetSet *aRTSet, int32_t aInputFrameID)
   // un-viewable and a more accurate pose prediction is not likely to
   // compensate.
   ovrLayerEyeFov layer;
+  memset(&layer, 0, sizeof(layer));
   layer.Header.Type = ovrLayerType_EyeFov;
   layer.Header.Flags = 0;
   layer.ColorTexture[0] = rts->textureSet;
@@ -607,6 +614,7 @@ VRHMDManagerOculus::Init()
     mOculusThread = already_AddRefed<nsIThread>(thread);
 
     ovrInitParams params;
+    memset(&params, 0, sizeof(params));
     params.Flags = ovrInit_RequestVersion;
     params.RequestedMinorVersion = OVR_MINOR_VERSION;
     params.LogCallback = nullptr;

gfx/vr/gfxVROculus050.cpp

@@ -543,6 +543,7 @@ VRHMDManagerOculus050::Init()
     mOculusThread = already_AddRefed<nsIThread>(thread);
 
     ovrInitParams params;
+    memset(&params, 0, sizeof(params));
     params.Flags = ovrInit_RequestVersion;
     params.RequestedMinorVersion = LIBOVR_MINOR_VERSION;
     params.LogCallback = nullptr;

layout/base/nsIPresShell.h

@@ -45,7 +45,6 @@
 #include "nsRefPtrHashtable.h"
 #include "nsClassHashtable.h"
 #include "nsPresArena.h"
-#include "nsIImageLoadingContent.h"
 #include "nsMargin.h"
 #include "nsFrameState.h"
 
@@ -358,22 +357,25 @@ public:
   bool GetAuthorStyleDisabled() const;
 
   /*
-   * Called when stylesheets are added/removed/enabled/disabled to rebuild
+   * Called when stylesheets are added/removed/enabled/disabled to
-   * all style data for a given pres shell without necessarily reconstructing
+   * recompute style and clear other cached data as needed.  This will
-   * all of the frames.  This will not reconstruct style synchronously; if
+   * not reconstruct style synchronously; if you need to do that, call
-   * you need to do that, call FlushPendingNotifications to flush out style
+   * FlushPendingNotifications to flush out style reresolves.
-   * reresolves.
+   *
+   * This handles the the addition and removal of the various types of
+   * style rules that can be in CSS style sheets, such as @font-face
+   * rules and @counter-style rules.
+   *
+   * It requires that StyleSheetAdded, StyleSheetRemoved,
+   * StyleSheetApplicableStateChanged, StyleRuleAdded, StyleRuleRemoved,
+   * or StyleRuleChanged has been called on the style sheets that have
+   * changed.
+   *
    * // XXXbz why do we have this on the interface anyway?  The only consumer
    * is calling AddOverrideStyleSheet/RemoveOverrideStyleSheet, and I think
    * those should just handle reconstructing style data...
    */
-  virtual void ReconstructStyleDataExternal();
+  void RestyleForCSSRuleChanges();
-  void ReconstructStyleDataInternal();
-#ifdef MOZILLA_INTERNAL_API
-  void ReconstructStyleData() { ReconstructStyleDataInternal(); }
-#else
-  void ReconstructStyleData() { ReconstructStyleDataExternal(); }
-#endif
 
   /**
    * Update the style set somehow to take into account changed prefs which
@@ -1588,11 +1590,12 @@ public:
   virtual void RebuildApproximateFrameVisibility(nsRect* aRect = nullptr,
                                                  bool aRemoveOnly = false) = 0;
 
-  /// Ensures @aFrame is in the list of approximately visible frames.
+  /// Adds @aFrame to the list of frames which were visible within the
-  virtual void EnsureFrameInApproximatelyVisibleList(nsIFrame* aFrame) = 0;
+  /// displayport during the last paint.
+  virtual void MarkFrameVisibleInDisplayPort(nsIFrame* aFrame) = 0;
 
-  /// Removes @aFrame from the list of approximately visible frames if present.
+  /// Marks @aFrame nonvisible and removes it from all lists of visible frames.
-  virtual void RemoveFrameFromApproximatelyVisibleList(nsIFrame* aFrame) = 0;
+  virtual void MarkFrameNonvisible(nsIFrame* aFrame) = 0;
 
   /// Whether we should assume all frames are visible.
   virtual bool AssumeAllFramesVisible() = 0;

layout/base/nsPresShell.cpp

@@ -1184,8 +1184,9 @@ PresShell::Destroy()
   mSynthMouseMoveEvent.Revoke();
 
   mUpdateApproximateFrameVisibilityEvent.Revoke();
+  mNotifyCompositorOfVisibleRegionsChangeEvent.Revoke();
 
-  ClearApproximatelyVisibleFramesList(Some(OnNonvisible::DISCARD_IMAGES));
+  ClearVisibleFramesSets(Some(OnNonvisible::DISCARD_IMAGES));
 
   if (mCaret) {
     mCaret->Terminate();
@@ -1343,7 +1344,7 @@ nsIPresShell::SetAuthorStyleDisabled(bool aStyleDisabled)
 {
   if (aStyleDisabled != mStyleSet->GetAuthorStyleDisabled()) {
     mStyleSet->SetAuthorStyleDisabled(aStyleDisabled);
-    ReconstructStyleData();
+    RestyleForCSSRuleChanges();
 
     nsCOMPtr<nsIObserverService> observerService =
       mozilla::services::GetObserverService();
@@ -1452,7 +1453,7 @@ PresShell::AddUserSheet(nsISupports* aSheet)
 
   mStyleSet->EndUpdate();
 
-  ReconstructStyleData();
+  RestyleForCSSRuleChanges();
 }
 
 void
@@ -1468,7 +1469,7 @@ PresShell::AddAgentSheet(nsISupports* aSheet)
   }
 
   mStyleSet->AppendStyleSheet(SheetType::Agent, sheet);
-  ReconstructStyleData();
+  RestyleForCSSRuleChanges();
 }
 
 void
@@ -1491,7 +1492,7 @@ PresShell::AddAuthorSheet(nsISupports* aSheet)
     mStyleSet->AppendStyleSheet(SheetType::Doc, sheet);
   }
 
-  ReconstructStyleData();
+  RestyleForCSSRuleChanges();
 }
 
 void
@@ -1504,7 +1505,7 @@ PresShell::RemoveSheet(SheetType aType, nsISupports* aSheet)
   }
 
   mStyleSet->RemoveStyleSheet(aType, sheet);
-  ReconstructStyleData();
+  RestyleForCSSRuleChanges();
 }
 
 NS_IMETHODIMP
@@ -2407,7 +2408,7 @@ PresShell::EndUpdate(nsIDocument *aDocument, nsUpdateType aUpdateType)
   if (aUpdateType & UPDATE_STYLE) {
     mStyleSet->EndUpdate();
     if (mStylesHaveChanged || !mChangedScopeStyleRoots.IsEmpty())
-      ReconstructStyleData();
+      RestyleForCSSRuleChanges();
   }
 
   mFrameConstructor->EndUpdate();
@@ -4440,7 +4441,7 @@ PresShell::ReconstructFrames(void)
 }
 
 void
-nsIPresShell::ReconstructStyleDataInternal()
+nsIPresShell::RestyleForCSSRuleChanges()
 {
   AutoTArray<RefPtr<mozilla::dom::Element>,1> scopeRoots;
   mChangedScopeStyleRoots.SwapElements(scopeRoots);
@@ -4490,12 +4491,6 @@ nsIPresShell::ReconstructStyleDataInternal()
   }
 }
 
-void
-nsIPresShell::ReconstructStyleDataExternal()
-{
-  ReconstructStyleDataInternal();
-}
-
 void
 PresShell::RecordStyleSheetChange(StyleSheetHandle aStyleSheet)
 {
@@ -4575,6 +4570,71 @@ PresShell::GetPlaceholderFrameFor(nsIFrame* aFrame) const
   return mFrameConstructor->GetPlaceholderFrameFor(aFrame);
 }
 
+void
+PresShell::NotifyCompositorOfVisibleRegionsChange()
+{
+  mNotifyCompositorOfVisibleRegionsChangeEvent.Revoke();
+
+  if (!mVisibleRegions) {
+    return;
+  }
+
+  // Retrieve the layers ID and pres shell ID.
+  TabChild* tabChild = TabChild::GetFrom(this);
+  if (!tabChild) {
+    return;
+  }
+
+  const uint64_t layersId = tabChild->LayersId();
+  const uint32_t presShellId = GetPresShellId();
+
+  // Retrieve the CompositorBridgeChild.
+  LayerManager* layerManager = GetLayerManager();
+  if (!layerManager) {
+    return;
+  }
+
+  ClientLayerManager* clientLayerManager = layerManager->AsClientLayerManager();
+  if (!clientLayerManager) {
+    return;
+  }
+
+  CompositorBridgeChild* compositorChild = clientLayerManager->GetCompositorBridgeChild();
+  if (!compositorChild) {
+    return;
+  }
+
+  // Clear the old visible regions associated with this document.
+  compositorChild->SendClearVisibleRegions(layersId, presShellId);
+
+  // Send the new visible regions to the compositor.
+  for (auto iter = mVisibleRegions->mApproximate.ConstIter();
+      !iter.Done();
+      iter.Next()) {
+    const ViewID viewId = iter.Key();
+    const CSSIntRegion* region = iter.UserData();
+    MOZ_ASSERT(region);
+
+    const ScrollableLayerGuid guid(layersId, presShellId, viewId);
+
+    compositorChild->SendUpdateVisibleRegion(VisibilityCounter::MAY_BECOME_VISIBLE,
+                                             guid, *region);
+  }
+
+  for (auto iter = mVisibleRegions->mInDisplayPort.ConstIter();
+      !iter.Done();
+      iter.Next()) {
+    const ViewID viewId = iter.Key();
+    const CSSIntRegion* region = iter.UserData();
+    MOZ_ASSERT(region);
+
+    const ScrollableLayerGuid guid(layersId, presShellId, viewId);
+
+    compositorChild->SendUpdateVisibleRegion(VisibilityCounter::IN_DISPLAYPORT,
+                                             guid, *region);
+  }
+}
+
 nsresult
 PresShell::RenderDocument(const nsRect& aRect, uint32_t aFlags,
                           nscolor aBackgroundColor,
@@ -4686,6 +4746,9 @@ PresShell::RenderDocument(const nsRect& aRect, uint32_t aFlags,
   nsLayoutUtils::PaintFrame(&rc, rootFrame, nsRegion(aRect),
                             aBackgroundColor, flags);
 
+  // We don't call NotifyCompositorOfVisibleRegionsChange here because we're
+  // not painting to the window, and hence there should be no change.
+
   return NS_OK;
 }
 
@@ -4838,12 +4901,12 @@ PresShell::CreateRangePaintInfo(nsIDOMRange* aRange,
       ancestorFrame = ancestorFrame->GetParent();
   }
 
-  if (!ancestorFrame)
+  if (!ancestorFrame) {
     return nullptr;
-
+  }
-  auto info = MakeUnique<RangePaintInfo>(range, ancestorFrame);
 
   // get a display list containing the range
+  auto info = MakeUnique<RangePaintInfo>(range, ancestorFrame);
   info->mBuilder.SetIncludeAllOutOfFlows();
   if (aForPrimarySelection) {
     info->mBuilder.SetSelectedFramesOnly();
@@ -5576,17 +5639,14 @@ PresShell::ProcessSynthMouseMoveEvent(bool aFromScroll)
   }
 }
 
-static void
+void
-AddFrameToVisibleRegions(nsIFrame* aFrame,
+PresShell::AddFrameToVisibleRegions(nsIFrame* aFrame, VisibilityCounter aForCounter)
-                         nsViewManager* aViewManager,
-                         Maybe<VisibleRegions>& aVisibleRegions)
 {
-  if (!aVisibleRegions) {
+  if (!mVisibleRegions) {
     return;
   }
 
   MOZ_ASSERT(aFrame);
-  MOZ_ASSERT(aViewManager);
 
   // Retrieve the view ID for this frame (which we obtain from the enclosing
   // scrollable frame).
@@ -5621,20 +5681,22 @@ AddFrameToVisibleRegions(nsIFrame* aFrame,
     return;
   }
 
-  CSSIntRegion* regionForView = aVisibleRegions->LookupOrAdd(viewID);
+  VisibleRegions& regions = aForCounter == VisibilityCounter::MAY_BECOME_VISIBLE
+                          ? mVisibleRegions->mApproximate
+                          : mVisibleRegions->mInDisplayPort;
+  CSSIntRegion* regionForView = regions.LookupOrAdd(viewID);
   MOZ_ASSERT(regionForView);
 
   regionForView->OrWith(CSSPixel::FromAppUnitsRounded(frameRectInScrolledFrameSpace));
 }
 
 /* static */ void
-PresShell::MarkFramesInListApproximatelyVisible(const nsDisplayList& aList,
+PresShell::MarkFramesInListApproximatelyVisible(const nsDisplayList& aList)
-                                                Maybe<VisibleRegions>& aVisibleRegions)
 {
   for (nsDisplayItem* item = aList.GetBottom(); item; item = item->GetAbove()) {
     nsDisplayList* sublist = item->GetChildren();
     if (sublist) {
-      MarkFramesInListApproximatelyVisible(*sublist, aVisibleRegions);
+      MarkFramesInListApproximatelyVisible(*sublist);
       continue;
     }
 
@@ -5652,128 +5714,56 @@ PresShell::MarkFramesInListApproximatelyVisible(const nsDisplayList& aList,
     presShell->mApproximatelyVisibleFrames.PutEntry(frame);
     if (presShell->mApproximatelyVisibleFrames.Count() > count) {
       // The frame was added to mApproximatelyVisibleFrames, so increment its visible count.
-      frame->IncApproximateVisibleCount();
+      frame->IncVisibilityCount(VisibilityCounter::MAY_BECOME_VISIBLE);
     }
 
-    AddFrameToVisibleRegions(frame, presShell->mViewManager, aVisibleRegions);
+    presShell->AddFrameToVisibleRegions(frame, VisibilityCounter::MAY_BECOME_VISIBLE);
-  }
-}
-
-void
-PresShell::ReportBadStateDuringVisibilityUpdate()
-{
-  if (!NS_IsMainThread()) {
-    gfxCriticalNote << "Got null frame in frame visibility: off-main-thread";
-  }
-  if (mIsZombie) {
-    gfxCriticalNote << "Got null frame in frame visibility: mIsZombie";
-  }
-  if (mIsDestroying) {
-    gfxCriticalNote << "Got null frame in frame visibility: mIsDestroying";
-  }
-  if (mIsReflowing) {
-    gfxCriticalNote << "Got null frame in frame visibility: mIsReflowing";
-  }
-  if (mPaintingIsFrozen) {
-    gfxCriticalNote << "Got null frame in frame visibility: mPaintingIsFrozen";
-  }
-  if (mForwardingContainer) {
-    gfxCriticalNote << "Got null frame in frame visibility: mForwardingContainer";
-  }
-  if (mIsNeverPainting) {
-    gfxCriticalNote << "Got null frame in frame visibility: mIsNeverPainting";
-  }
-  if (mIsDocumentGone) {
-    gfxCriticalNote << "Got null frame in frame visibility: mIsDocumentGone";
-  }
-  if (!nsContentUtils::IsSafeToRunScript()) {
-    gfxCriticalNote << "Got null frame in frame visibility: not safe to run script";
-  }
-}
-
-void
-PresShell::SetInFrameVisibilityUpdate(bool aState)
-{
-  mInFrameVisibilityUpdate = aState;
-}
-
-static void
-NotifyCompositorOfVisibleRegionsChange(PresShell* aPresShell,
-                                       const Maybe<VisibleRegions>& aRegions)
-{
-  if (!aRegions) {
-    return;
-  }
-
-  MOZ_ASSERT(aPresShell);
-
-  // Retrieve the layers ID and pres shell ID.
-  TabChild* tabChild = TabChild::GetFrom(aPresShell);
-  if (!tabChild) {
-    return;
-  }
-
-  const uint64_t layersId = tabChild->LayersId();
-  const uint32_t presShellId = aPresShell->GetPresShellId();
-
-  // Retrieve the CompositorBridgeChild.
-  LayerManager* layerManager = aPresShell->GetLayerManager();
-  if (!layerManager) {
-    return;
-  }
-
-  ClientLayerManager* clientLayerManager = layerManager->AsClientLayerManager();
-  if (!clientLayerManager) {
-    return;
-  }
-
-  CompositorBridgeChild* compositorChild = clientLayerManager->GetCompositorBridgeChild();
-  if (!compositorChild) {
-    return;
-  }
-
-  // Clear the old approximately visible regions associated with this document.
-  compositorChild->SendClearApproximatelyVisibleRegions(layersId, presShellId);
-
-  // Send the new approximately visible regions to the compositor.
-  for (auto iter = aRegions->ConstIter(); !iter.Done(); iter.Next()) {
-    const ViewID viewId = iter.Key();
-    const CSSIntRegion* region = iter.UserData();
-    MOZ_ASSERT(region);
-
-    const ScrollableLayerGuid guid(layersId, presShellId, viewId);
-
-    compositorChild->SendNotifyApproximatelyVisibleRegion(guid, *region);
   }
 }
 
 /* static */ void
-PresShell::DecApproximateVisibleCount(VisibleFrames& aFrames,
+PresShell::DecVisibleCount(const VisibleFrames& aFrames,
-                                      Maybe<OnNonvisible> aNonvisibleAction
+                           VisibilityCounter aCounter,
-                                        /* = Nothing() */)
+                           Maybe<OnNonvisible> aNonvisibleAction /* = Nothing() */)
 {
-  for (auto iter = aFrames.Iter(); !iter.Done(); iter.Next()) {
+  for (auto iter = aFrames.ConstIter(); !iter.Done(); iter.Next()) {
     nsIFrame* frame = iter.Get()->GetKey();
-
-    if (MOZ_UNLIKELY(!frame)) {
-      // We are about to crash, annotate crash report with some info that might
-      // help debug the crash (bug 1251150)
-      ReportBadStateDuringVisibilityUpdate();
-    }
-
-    SetInFrameVisibilityUpdate(true);
-
     // Decrement the frame's visible count if we're still tracking its
     // visibility. (We may not be, if the frame disabled visibility tracking
     // after we added it to the visible frames list.)
     if (frame->TrackingVisibility()) {
-      frame->DecApproximateVisibleCount(aNonvisibleAction);
+      frame->DecVisibilityCount(aCounter, aNonvisibleAction);
     }
-
-    SetInFrameVisibilityUpdate(false);
   }
 }
 
+void
+PresShell::InitVisibleRegionsIfVisualizationEnabled(VisibilityCounter aForCounter)
+{
+  // If we're visualizing visible regions, initialize a
+  // VisibleRegionsContainer to store them.  Visibility-related functions we
+  // call will only do the work of populating this object and sending it to
+  // the compositor if we've created it, so we don't need to check the prefs
+  // everywhere.
+  if (!gfxPrefs::APZMinimap() ||
+      !gfxPrefs::APZMinimapVisibilityEnabled()) {
+    mVisibleRegions = nullptr;
+    return;
+  }
+
+  if (mVisibleRegions) {
+    // Clear the regions we're about to update. We don't want to clear both,
+    // or the two visibility tracking methods will interfere with each other.
+    VisibleRegions& regions = aForCounter == VisibilityCounter::MAY_BECOME_VISIBLE
+                            ? mVisibleRegions->mApproximate
+                            : mVisibleRegions->mInDisplayPort;
+    regions.Clear();
+    return;
+  }
+
+  mVisibleRegions = MakeUnique<VisibleRegionsContainer>();
+}
+
 void
 PresShell::RebuildApproximateFrameVisibilityDisplayList(const nsDisplayList& aList)
 {
@@ -5785,70 +5775,72 @@ PresShell::RebuildApproximateFrameVisibilityDisplayList(const nsDisplayList& aLi
   VisibleFrames oldApproximatelyVisibleFrames;
   mApproximatelyVisibleFrames.SwapElements(oldApproximatelyVisibleFrames);
 
-  // If we're visualizing visible regions, create a VisibleRegions object to
+  InitVisibleRegionsIfVisualizationEnabled(VisibilityCounter::MAY_BECOME_VISIBLE);
-  // store information about them. The functions we call will populate this
-  // object and send it to the compositor only if it's Some(), so we don't
-  // need to check the prefs everywhere.
-  Maybe<VisibleRegions> visibleRegions;
-  if (gfxPrefs::APZMinimap() && gfxPrefs::APZMinimapVisibilityEnabled()) {
-    visibleRegions.emplace();
-  }
 
-  MarkFramesInListApproximatelyVisible(aList, visibleRegions);
+  MarkFramesInListApproximatelyVisible(aList);
 
-  DecApproximateVisibleCount(oldApproximatelyVisibleFrames);
+  DecVisibleCount(oldApproximatelyVisibleFrames,
+                  VisibilityCounter::MAY_BECOME_VISIBLE);
 
-  NotifyCompositorOfVisibleRegionsChange(this, visibleRegions);
+  NotifyCompositorOfVisibleRegionsChange();
 }
 
 /* static */ void
-PresShell::ClearApproximateFrameVisibilityVisited(nsView* aView, bool aClear)
+PresShell::ClearVisibleFramesForUnvisitedPresShells(nsView* aView, bool aClear)
 {
   nsViewManager* vm = aView->GetViewManager();
   if (aClear) {
     PresShell* presShell = static_cast<PresShell*>(vm->GetPresShell());
     if (!presShell->mApproximateFrameVisibilityVisited) {
-      presShell->ClearApproximatelyVisibleFramesList();
+      presShell->ClearVisibleFramesSets();
     }
     presShell->mApproximateFrameVisibilityVisited = false;
   }
   for (nsView* v = aView->GetFirstChild(); v; v = v->GetNextSibling()) {
-    ClearApproximateFrameVisibilityVisited(v, v->GetViewManager() != vm);
+    ClearVisibleFramesForUnvisitedPresShells(v, v->GetViewManager() != vm);
   }
 }
 
 void
-PresShell::ClearApproximatelyVisibleFramesList(Maybe<OnNonvisible> aNonvisibleAction
+PresShell::ClearVisibleFramesSets(Maybe<OnNonvisible> aNonvisibleAction
-                                                 /* = Nothing() */)
+                                    /* = Nothing() */)
 {
-  if (mInFrameVisibilityUpdate) {
+  DecVisibleCount(mApproximatelyVisibleFrames,
-    gfxCriticalNoteOnce << "ClearApproximatelyVisibleFramesList is re-entering on "
+                  VisibilityCounter::MAY_BECOME_VISIBLE,
-                        << (NS_IsMainThread() ? "" : "non-") << "main thread";
+                  aNonvisibleAction);
-  }
-  DecApproximateVisibleCount(mApproximatelyVisibleFrames, aNonvisibleAction);
   mApproximatelyVisibleFrames.Clear();
+
+  DecVisibleCount(mInDisplayPortFrames,
+                  VisibilityCounter::IN_DISPLAYPORT,
+                  aNonvisibleAction);
+  mInDisplayPortFrames.Clear();
+
+  if (mVisibleRegions) {
+    mVisibleRegions->mApproximate.Clear();
+    mVisibleRegions->mInDisplayPort.Clear();
+    NotifyCompositorOfVisibleRegionsChange();
+  }
 }
 
 void
 PresShell::MarkFramesInSubtreeApproximatelyVisible(nsIFrame* aFrame,
                                                    const nsRect& aRect,
-                                                   Maybe<VisibleRegions>& aVisibleRegions,
                                                    bool aRemoveOnly /* = false */)
 {
   MOZ_ASSERT(aFrame->PresContext()->PresShell() == this, "wrong presshell");
 
   if (aFrame->TrackingVisibility() &&
       aFrame->StyleVisibility()->IsVisible() &&
-      (!aRemoveOnly || aFrame->GetVisibility() == Visibility::APPROXIMATELY_VISIBLE)) {
+      (!aRemoveOnly || aFrame->IsVisibleOrMayBecomeVisibleSoon())) {
     MOZ_ASSERT(!AssumeAllFramesVisible());
     uint32_t count = mApproximatelyVisibleFrames.Count();
     mApproximatelyVisibleFrames.PutEntry(aFrame);
     if (mApproximatelyVisibleFrames.Count() > count) {
       // The frame was added to mApproximatelyVisibleFrames, so increment its visible count.
-      aFrame->IncApproximateVisibleCount();
+      aFrame->IncVisibilityCount(VisibilityCounter::MAY_BECOME_VISIBLE);
     }
 
-    AddFrameToVisibleRegions(aFrame, mViewManager, aVisibleRegions);
+    AddFrameToVisibleRegions(aFrame, VisibilityCounter::MAY_BECOME_VISIBLE);
   }
 
   nsSubDocumentFrame* subdocFrame = do_QueryFrame(aFrame);
@@ -5917,7 +5909,7 @@ PresShell::MarkFramesInSubtreeApproximatelyVisible(nsIFrame* aFrame,
           }
         }
       }
-      MarkFramesInSubtreeApproximatelyVisible(child, r, aVisibleRegions);
+      MarkFramesInSubtreeApproximatelyVisible(child, r);
     }
   }
 }
@@ -5934,35 +5926,24 @@ PresShell::RebuildApproximateFrameVisibility(nsRect* aRect,
     return;
   }
 
-  if (mInFrameVisibilityUpdate) {
-    gfxCriticalNoteOnce << "RebuildApproximateFrameVisibility is re-entering on "
-                        << (NS_IsMainThread() ? "" : "non-") << "main thread";
-  }
-
   // Remove the entries of the mApproximatelyVisibleFrames hashtable and put
   // them in oldApproximatelyVisibleFrames.
   VisibleFrames oldApproximatelyVisibleFrames;
   mApproximatelyVisibleFrames.SwapElements(oldApproximatelyVisibleFrames);
 
-  // If we're visualizing visible regions, create a VisibleRegions object to
+  InitVisibleRegionsIfVisualizationEnabled(VisibilityCounter::MAY_BECOME_VISIBLE);
-  // store information about them. The functions we call will populate this
-  // object and send it to the compositor only if it's Some(), so we don't
-  // need to check the prefs everywhere.
-  Maybe<VisibleRegions> visibleRegions;
-  if (gfxPrefs::APZMinimap() && gfxPrefs::APZMinimapVisibilityEnabled()) {
-    visibleRegions.emplace();
-  }
 
   nsRect vis(nsPoint(0, 0), rootFrame->GetSize());
   if (aRect) {
     vis = *aRect;
   }
 
-  MarkFramesInSubtreeApproximatelyVisible(rootFrame, vis, visibleRegions, aRemoveOnly);
+  MarkFramesInSubtreeApproximatelyVisible(rootFrame, vis, aRemoveOnly);
 
-  DecApproximateVisibleCount(oldApproximatelyVisibleFrames);
+  DecVisibleCount(oldApproximatelyVisibleFrames,
+                  VisibilityCounter::MAY_BECOME_VISIBLE);
 
-  NotifyCompositorOfVisibleRegionsChange(this, visibleRegions);
+  NotifyCompositorOfVisibleRegionsChange();
 }
 
 void
@@ -5986,12 +5967,12 @@ PresShell::DoUpdateApproximateFrameVisibility(bool aRemoveOnly)
   // call update on that frame
   nsIFrame* rootFrame = GetRootFrame();
   if (!rootFrame) {
-    ClearApproximatelyVisibleFramesList(Some(OnNonvisible::DISCARD_IMAGES));
+    ClearVisibleFramesSets(Some(OnNonvisible::DISCARD_IMAGES));
     return;
   }
 
   RebuildApproximateFrameVisibility(/* aRect = */ nullptr, aRemoveOnly);
-  ClearApproximateFrameVisibilityVisited(rootFrame->GetView(), true);
+  ClearVisibleFramesForUnvisitedPresShells(rootFrame->GetView(), true);
 
 #ifdef DEBUG_FRAME_VISIBILITY_DISPLAY_LIST
   // This can be used to debug the frame walker by comparing beforeFrameList
@@ -6005,7 +5986,8 @@ PresShell::DoUpdateApproximateFrameVisibility(bool aRemoveOnly)
   if (rootScroll) {
     nsIContent* content = rootScroll->GetContent();
     if (content) {
-      Unused << nsLayoutUtils::GetDisplayPort(content, &updateRect, RelativeTo::ScrollFrame);
+      Unused << nsLayoutUtils::GetDisplayPortForVisibilityTesting(content, &updateRect,
+        RelativeTo::ScrollFrame);
     }
 
     if (IgnoringViewportScrolling()) {
@@ -6020,7 +6002,7 @@ PresShell::DoUpdateApproximateFrameVisibility(bool aRemoveOnly)
 
   RebuildApproximateFrameVisibilityDisplayList(list);
 
-  ClearApproximateFrameVisibilityVisited(rootFrame->GetView(), true);
+  ClearVisibleFramesForUnvisitedPresShells(rootFrame->GetView(), true);
 
   list.DeleteAll();
 #endif
@@ -6125,14 +6107,16 @@ PresShell::ScheduleApproximateFrameVisibilityUpdateNow()
 }
 
 void
-PresShell::EnsureFrameInApproximatelyVisibleList(nsIFrame* aFrame)
+PresShell::MarkFrameVisibleInDisplayPort(nsIFrame* aFrame)
 {
   if (!aFrame->TrackingVisibility()) {
     return;
   }
 
   if (AssumeAllFramesVisible()) {
-    aFrame->IncApproximateVisibleCount();
+    if (aFrame->GetVisibility() != Visibility::IN_DISPLAYPORT) {
+      aFrame->IncVisibilityCount(VisibilityCounter::IN_DISPLAYPORT);
+    }
     return;
   }
 
@@ -6145,20 +6129,31 @@ PresShell::EnsureFrameInApproximatelyVisibleList(nsIFrame* aFrame)
   }
 #endif
 
-  if (mInFrameVisibilityUpdate) {
+  if (!mInDisplayPortFrames.Contains(aFrame)) {
-    gfxCriticalNoteOnce << "EnsureFrameInApproximatelyVisibleList is re-entering on "
+    MOZ_ASSERT(!AssumeAllFramesVisible());
-                        << (NS_IsMainThread() ? "" : "non-") << "main thread";
+    mInDisplayPortFrames.PutEntry(aFrame);
+    aFrame->IncVisibilityCount(VisibilityCounter::IN_DISPLAYPORT);
   }
 
-  if (!mApproximatelyVisibleFrames.Contains(aFrame)) {
+  AddFrameToVisibleRegions(aFrame, VisibilityCounter::IN_DISPLAYPORT);
-    MOZ_ASSERT(!AssumeAllFramesVisible());
+}
-    mApproximatelyVisibleFrames.PutEntry(aFrame);
+
-    aFrame->IncApproximateVisibleCount();
+static void
+RemoveFrameFromVisibleSet(nsIFrame* aFrame,
+                          VisibleFrames& aSet,
+                          VisibilityCounter aCounter)
+{
+  uint32_t count = aSet.Count();
+  aSet.RemoveEntry(aFrame);
+
+  if (aFrame->TrackingVisibility() && aSet.Count() < count) {
+    aFrame->DecVisibilityCount(aCounter);
   }
+
 }
 
 void
-PresShell::RemoveFrameFromApproximatelyVisibleList(nsIFrame* aFrame)
+PresShell::MarkFrameNonvisible(nsIFrame* aFrame)
 {
 #ifdef DEBUG
   // Make sure it's in this pres shell.
@@ -6171,24 +6166,16 @@ PresShell::RemoveFrameFromApproximatelyVisibleList(nsIFrame* aFrame)
 
   if (AssumeAllFramesVisible()) {
     MOZ_ASSERT(mApproximatelyVisibleFrames.Count() == 0,
-               "Shouldn't have any frames in the table");
+               "Shouldn't have any frames in the approximate visibility set");
+    MOZ_ASSERT(mInDisplayPortFrames.Count() == 0,
+               "Shouldn't have any frames in the in-displayport visibility set");
     return;
   }
 
-  if (mInFrameVisibilityUpdate) {
+  RemoveFrameFromVisibleSet(aFrame, mApproximatelyVisibleFrames,
-    gfxCriticalNoteOnce << "RemoveFrameFromApproximatelyVisibleList is re-entering on "
+                            VisibilityCounter::MAY_BECOME_VISIBLE);
-                        << (NS_IsMainThread() ? "" : "non-") << "main thread";
+  RemoveFrameFromVisibleSet(aFrame, mInDisplayPortFrames,
-  }
+                            VisibilityCounter::IN_DISPLAYPORT);
-
-  uint32_t count = mApproximatelyVisibleFrames.Count();
-  mApproximatelyVisibleFrames.RemoveEntry(aFrame);
-
-  if (aFrame->TrackingVisibility() &&
-      mApproximatelyVisibleFrames.Count() < count) {
-    // aFrame was in the hashtable, and we're still tracking its visibility,
-    // so we need to decrement its visible count.
-    aFrame->DecApproximateVisibleCount();
-  }
 }
 
 class nsAutoNotifyDidPaint
@@ -6376,8 +6363,30 @@ PresShell::Paint(nsView*        aViewToPaint,
   }
 
   if (frame) {
+    // Remove the entries of the mInDisplayPortFrames hashtable and put them
+    // in oldInDisplayPortFrames.
+    VisibleFrames oldInDisplayPortFrames;
+    mInDisplayPortFrames.SwapElements(oldInDisplayPortFrames);
+
+    InitVisibleRegionsIfVisualizationEnabled(VisibilityCounter::IN_DISPLAYPORT);
+
     // We can paint directly into the widget using its layer manager.
     nsLayoutUtils::PaintFrame(nullptr, frame, aDirtyRegion, bgcolor, flags);
+
+    DecVisibleCount(oldInDisplayPortFrames, VisibilityCounter::IN_DISPLAYPORT);
+
+    if (mVisibleRegions &&
+        !mNotifyCompositorOfVisibleRegionsChangeEvent.IsPending()) {
+      // Asynchronously notify the compositor of the new visible regions,
+      // since this is happening during a paint and updating the visible
+      // regions triggers a recomposite.
+      RefPtr<nsRunnableMethod<PresShell>> event =
+        NS_NewRunnableMethod(this, &PresShell::NotifyCompositorOfVisibleRegionsChange);
+      if (NS_SUCCEEDED(NS_DispatchToMainThread(event))) {
+        mNotifyCompositorOfVisibleRegionsChangeEvent = event;
+      }
+    }
+
     return;
   }
 
@@ -9024,6 +9033,7 @@ void
 PresShell::Freeze()
 {
   mUpdateApproximateFrameVisibilityEvent.Revoke();
+  mNotifyCompositorOfVisibleRegionsChangeEvent.Revoke();
 
   MaybeReleaseCapturingContent();
 
@@ -11047,11 +11057,6 @@ PresShell::UpdateImageLockingState()
   nsresult rv = mDocument->SetImageLockingState(locked);
 
   if (locked) {
-    if (mInFrameVisibilityUpdate) {
-      gfxCriticalNoteOnce << "UpdateImageLockingState is re-entering on "
-                          << (NS_IsMainThread() ? "" : "non-") << "main thread";
-    }
-
     // Request decodes for visible image frames; we want to start decoding as
     // quickly as possible when we get foregrounded to minimize flashing.
     for (auto iter = mApproximatelyVisibleFrames.Iter(); !iter.Done(); iter.Next()) {
@@ -11091,6 +11096,11 @@ PresShell::AddSizeOfIncludingThis(MallocSizeOf aMallocSizeOf,
     *aPresShellSize += mCaret->SizeOfIncludingThis(aMallocSizeOf);
   }
   *aPresShellSize += mApproximatelyVisibleFrames.ShallowSizeOfExcludingThis(aMallocSizeOf);
+  *aPresShellSize += mInDisplayPortFrames.ShallowSizeOfExcludingThis(aMallocSizeOf);
+  *aPresShellSize += mVisibleRegions
+                   ? mVisibleRegions->mApproximate.ShallowSizeOfIncludingThis(aMallocSizeOf) +
+                     mVisibleRegions->mInDisplayPort.ShallowSizeOfIncludingThis(aMallocSizeOf)
+                   : 0;
   *aPresShellSize += mFramesToDirty.ShallowSizeOfExcludingThis(aMallocSizeOf);
   *aPresShellSize += aArenaObjectsSize->mOther;
 

layout/base/nsPresShell.h

@@ -38,6 +38,7 @@
 #include "mozilla/StyleSetHandle.h"
 #include "mozilla/UniquePtr.h"
 #include "MobileViewportManager.h"
+#include "Visibility.h"
 #include "ZoomConstraintsClient.h"
 
 class nsRange;
@@ -79,6 +80,8 @@ class PresShell final : public nsIPresShell,
   template <typename T> using Maybe = mozilla::Maybe<T>;
   using Nothing = mozilla::Nothing;
   using OnNonvisible = mozilla::OnNonvisible;
+  template <typename T> using UniquePtr = mozilla::UniquePtr<T>;
+  using VisibilityCounter = mozilla::VisibilityCounter;
   using VisibleFrames = mozilla::VisibleFrames;
   using VisibleRegions = mozilla::VisibleRegions;
 
@@ -402,8 +405,8 @@ public:
   void RebuildApproximateFrameVisibility(nsRect* aRect = nullptr,
                                          bool aRemoveOnly = false) override;
 
-  void EnsureFrameInApproximatelyVisibleList(nsIFrame* aFrame) override;
+  void MarkFrameVisibleInDisplayPort(nsIFrame* aFrame) override;
-  void RemoveFrameFromApproximatelyVisibleList(nsIFrame* aFrame) override;
+  void MarkFrameNonvisible(nsIFrame* aFrame) override;
 
   bool AssumeAllFramesVisible() override;
 
@@ -765,27 +768,46 @@ protected:
   void UpdateApproximateFrameVisibility();
   void DoUpdateApproximateFrameVisibility(bool aRemoveOnly);
 
-  void ClearApproximatelyVisibleFramesList(Maybe<mozilla::OnNonvisible> aNonvisibleAction
+  void ClearVisibleFramesSets(Maybe<OnNonvisible> aNonvisibleAction = Nothing());
-                                             = Nothing());
+  static void ClearVisibleFramesForUnvisitedPresShells(nsView* aView, bool aClear);
-  static void ClearApproximateFrameVisibilityVisited(nsView* aView, bool aClear);
+  static void MarkFramesInListApproximatelyVisible(const nsDisplayList& aList);
-  static void MarkFramesInListApproximatelyVisible(const nsDisplayList& aList,
-                                                   Maybe<VisibleRegions>& aVisibleRegions);
   void MarkFramesInSubtreeApproximatelyVisible(nsIFrame* aFrame,
                                                const nsRect& aRect,
-                                               Maybe<VisibleRegions>& aVisibleRegions,
                                                bool aRemoveOnly = false);
 
-  void DecApproximateVisibleCount(VisibleFrames& aFrames,
+  void DecVisibleCount(const VisibleFrames& aFrames,
-                                  Maybe<OnNonvisible> aNonvisibleAction = Nothing());
+                       VisibilityCounter aCounter,
-  void ReportBadStateDuringVisibilityUpdate();
+                       Maybe<OnNonvisible> aNonvisibleAction = Nothing());
-  void SetInFrameVisibilityUpdate(bool aState);
+
+  void InitVisibleRegionsIfVisualizationEnabled(VisibilityCounter aForCounter);
+  void AddFrameToVisibleRegions(nsIFrame* aFrame, VisibilityCounter aForCounter);
+  void NotifyCompositorOfVisibleRegionsChange();
 
   nsRevocableEventPtr<nsRunnableMethod<PresShell>> mUpdateApproximateFrameVisibilityEvent;
+  nsRevocableEventPtr<nsRunnableMethod<PresShell>> mNotifyCompositorOfVisibleRegionsChangeEvent;
 
   // A set of frames that were visible or could be visible soon at the time
   // that we last did an approximate frame visibility update.
   VisibleFrames mApproximatelyVisibleFrames;
 
+  // A set of frames that were visible in the displayport the last time we painted.
+  VisibleFrames mInDisplayPortFrames;
+
+  struct VisibleRegionsContainer
+  {
+    // The approximately visible regions calculated during the last update to
+    // approximate frame visibility.
+    VisibleRegions mApproximate;
+
+    // The in-displayport visible regions calculated during the last paint.
+    VisibleRegions mInDisplayPort;
+  };
+
+  // The most recent visible regions we've computed. Only non-null if the APZ
+  // minimap visibility visualization was enabled during the last visibility
+  // update.
+  UniquePtr<VisibleRegionsContainer> mVisibleRegions;
+
 
   //////////////////////////////////////////////////////////////////////////////
   // Methods for dispatching KeyboardEvent and BeforeAfterKeyboardEvent.
@@ -952,8 +974,6 @@ protected:
   // Whether the widget has received a paint message yet.
   bool                      mHasReceivedPaintMessage : 1;
 
-  bool                      mInFrameVisibilityUpdate : 1;
-
   static bool               sDisableNonTestMouseEvents;
 };
 

layout/forms/nsColorControlFrame.cpp

@@ -20,8 +20,8 @@
 
 using mozilla::dom::Element;
 
-nsColorControlFrame::nsColorControlFrame(nsStyleContext* aContext):
+nsColorControlFrame::nsColorControlFrame(nsStyleContext* aContext)
-  nsColorControlFrameSuper(aContext)
+  : nsHTMLButtonControlFrame(aContext)
 {
 }
 
@@ -36,14 +36,14 @@ NS_IMPL_FRAMEARENA_HELPERS(nsColorControlFrame)
 NS_QUERYFRAME_HEAD(nsColorControlFrame)
   NS_QUERYFRAME_ENTRY(nsColorControlFrame)
   NS_QUERYFRAME_ENTRY(nsIAnonymousContentCreator)
-NS_QUERYFRAME_TAIL_INHERITING(nsColorControlFrameSuper)
+NS_QUERYFRAME_TAIL_INHERITING(nsHTMLButtonControlFrame)
 
 
 void nsColorControlFrame::DestroyFrom(nsIFrame* aDestructRoot)
 {
   nsFormControlFrame::RegUnRegAccessKey(static_cast<nsIFrame*>(this), false);
   nsContentUtils::DestroyAnonymousContent(&mColorContent);
-  nsColorControlFrameSuper::DestroyFrom(aDestructRoot);
+  nsHTMLButtonControlFrame::DestroyFrom(aDestructRoot);
 }
 
 nsIAtom*
@@ -126,7 +126,7 @@ nsColorControlFrame::AttributeChanged(int32_t  aNameSpaceID,
       aNameSpaceID == kNameSpaceID_None && nsGkAtoms::value == aAttribute) {
     UpdateColor();
   }
-  return nsColorControlFrameSuper::AttributeChanged(aNameSpaceID, aAttribute,
+  return nsHTMLButtonControlFrame::AttributeChanged(aNameSpaceID, aAttribute,
                                                     aModType);
 }
 

layout/forms/nsColorControlFrame.h

@@ -14,11 +14,9 @@ namespace mozilla {
 enum class CSSPseudoElementType : uint8_t;
 } // namespace mozilla
 
-typedef nsHTMLButtonControlFrame nsColorControlFrameSuper;
-
 // Class which implements the input type=color
 
-class nsColorControlFrame final : public nsColorControlFrameSuper,
+class nsColorControlFrame final : public nsHTMLButtonControlFrame,
                                   public nsIAnonymousContentCreator
 {
   typedef mozilla::CSSPseudoElementType CSSPseudoElementType;

layout/forms/nsFormControlFrame.cpp

@@ -17,8 +17,8 @@ using namespace mozilla;
 
 //#define FCF_NOISY
 
-nsFormControlFrame::nsFormControlFrame(nsStyleContext* aContext) :
+nsFormControlFrame::nsFormControlFrame(nsStyleContext* aContext)
-  nsFormControlFrameSuper(aContext)
+  : nsAtomicContainerFrame(aContext)
 {
 }
 
@@ -29,7 +29,7 @@ nsFormControlFrame::~nsFormControlFrame()
 nsIAtom*
 nsFormControlFrame::GetType() const
 {
-  return nsGkAtoms::formControlFrame; 
+  return nsGkAtoms::formControlFrame;
 }
 
 void
@@ -37,12 +37,12 @@ nsFormControlFrame::DestroyFrom(nsIFrame* aDestructRoot)
 {
   // Unregister the access key registered in reflow
   nsFormControlFrame::RegUnRegAccessKey(static_cast<nsIFrame*>(this), false);
-  nsFormControlFrameSuper::DestroyFrom(aDestructRoot);
+  nsAtomicContainerFrame::DestroyFrom(aDestructRoot);
 }
 
 NS_QUERYFRAME_HEAD(nsFormControlFrame)
   NS_QUERYFRAME_ENTRY(nsIFormControlFrame)
-NS_QUERYFRAME_TAIL_INHERITING(nsFormControlFrameSuper)
+NS_QUERYFRAME_TAIL_INHERITING(nsAtomicContainerFrame)
 
 /* virtual */ nscoord
 nsFormControlFrame::GetMinISize(nsRenderingContext *aRenderingContext)

layout/forms/nsFormControlFrame.h

@@ -11,14 +11,12 @@
 #include "nsAtomicContainerFrame.h"
 #include "nsDisplayList.h"
 
-typedef nsAtomicContainerFrame nsFormControlFrameSuper;
+/**
-
-/** 
  * nsFormControlFrame is the base class for radio buttons and
  * checkboxes.  It also has two static methods (RegUnRegAccessKey and
  * GetScreenHeight) that are used by other form controls.
  */
-class nsFormControlFrame : public nsFormControlFrameSuper,
+class nsFormControlFrame : public nsAtomicContainerFrame,
                            public nsIFormControlFrame
 {
 public:
@@ -33,7 +31,7 @@ public:
 
   virtual bool IsFrameOfType(uint32_t aFlags) const override
   {
-    return nsFormControlFrameSuper::IsFrameOfType(aFlags &
+    return nsAtomicContainerFrame::IsFrameOfType(aFlags &
       ~(nsIFrame::eReplaced | nsIFrame::eReplacedContainsBlock));
   }
 
@@ -68,11 +66,11 @@ public:
                   const mozilla::LogicalSize& aPadding,
                   bool aShrinkWrap) override;
 
-  /** 
+  /**
     * Respond to a gui event
     * @see nsIFrame::HandleEvent
     */
-  virtual nsresult HandleEvent(nsPresContext* aPresContext, 
+  virtual nsresult HandleEvent(nsPresContext* aPresContext,
                                mozilla::WidgetGUIEvent* aEvent,
                                nsEventStatus* aEventStatus) override;
 
@@ -117,7 +115,7 @@ protected:
 //-------------------------------------------------------------------------------------
 //  Utility methods for managing checkboxes and radiobuttons
 //-------------------------------------------------------------------------------------
-//   
+//
    /**
     * Get the state of the checked attribute.
     * @param aState set to true if the checked attribute is set,

layout/forms/nsImageControlFrame.cpp

@@ -15,8 +15,7 @@
 
 using namespace mozilla;
 
-typedef nsImageFrame nsImageControlFrameSuper;
+class nsImageControlFrame : public nsImageFrame,
-class nsImageControlFrame : public nsImageControlFrameSuper,
                             public nsIFormControlFrame
 {
 public:
@@ -56,13 +55,13 @@ public:
                              nsIFrame::Cursor& aCursor) override;
   // nsIFormContromFrame
   virtual void SetFocus(bool aOn, bool aRepaint) override;
-  virtual nsresult SetFormProperty(nsIAtom* aName, 
+  virtual nsresult SetFormProperty(nsIAtom* aName,
                                    const nsAString& aValue) override;
 };
 
 
-nsImageControlFrame::nsImageControlFrame(nsStyleContext* aContext):
+nsImageControlFrame::nsImageControlFrame(nsStyleContext* aContext)
-  nsImageControlFrameSuper(aContext)
+  : nsImageFrame(aContext)
 {
 }
 
@@ -76,7 +75,7 @@ nsImageControlFrame::DestroyFrom(nsIFrame* aDestructRoot)
   if (!GetPrevInFlow()) {
     nsFormControlFrame::RegUnRegAccessKey(this, false);
   }
-  nsImageControlFrameSuper::DestroyFrom(aDestructRoot);
+  nsImageFrame::DestroyFrom(aDestructRoot);
 }
 
 nsIFrame*
@@ -92,12 +91,12 @@ nsImageControlFrame::Init(nsIContent*       aContent,
                           nsContainerFrame* aParent,
                           nsIFrame*         aPrevInFlow)
 {
-  nsImageControlFrameSuper::Init(aContent, aParent, aPrevInFlow);
+  nsImageFrame::Init(aContent, aParent, aPrevInFlow);
 
   if (aPrevInFlow) {
     return;
   }
-  
+
   mContent->SetProperty(nsGkAtoms::imageClickedPoint,
                         new nsIntPoint(0, 0),
                         nsINode::DeleteProperty<nsIntPoint>);
@@ -105,7 +104,7 @@ nsImageControlFrame::Init(nsIContent*       aContent,
 
 NS_QUERYFRAME_HEAD(nsImageControlFrame)
   NS_QUERYFRAME_ENTRY(nsIFormControlFrame)
-NS_QUERYFRAME_TAIL_INHERITING(nsImageControlFrameSuper)
+NS_QUERYFRAME_TAIL_INHERITING(nsImageFrame)
 
 #ifdef ACCESSIBILITY
 a11y::AccType
@@ -122,7 +121,7 @@ nsImageControlFrame::AccessibleType()
 nsIAtom*
 nsImageControlFrame::GetType() const
 {
-  return nsGkAtoms::imageControlFrame; 
+  return nsGkAtoms::imageControlFrame;
 }
 
 void
@@ -136,10 +135,10 @@ nsImageControlFrame::Reflow(nsPresContext*           aPresContext,
   if (!GetPrevInFlow() && (mState & NS_FRAME_FIRST_REFLOW)) {
     nsFormControlFrame::RegUnRegAccessKey(this, true);
   }
-  return nsImageControlFrameSuper::Reflow(aPresContext, aDesiredSize, aReflowState, aStatus);
+  return nsImageFrame::Reflow(aPresContext, aDesiredSize, aReflowState, aStatus);
 }
 
-nsresult 
+nsresult
 nsImageControlFrame::HandleEvent(nsPresContext* aPresContext,
                                  WidgetGUIEvent* aEvent,
                                  nsEventStatus* aEventStatus)
@@ -175,11 +174,10 @@ nsImageControlFrame::HandleEvent(nsPresContext* aPresContext,
       TranslateEventCoords(pt, *lastClickPoint);
     }
   }
-  return nsImageControlFrameSuper::HandleEvent(aPresContext, aEvent,
+  return nsImageFrame::HandleEvent(aPresContext, aEvent, aEventStatus);
-                                               aEventStatus);
 }
 
-void 
+void
 nsImageControlFrame::SetFocus(bool aOn, bool aRepaint)
 {
 }

layout/generic/Visibility.h

@@ -8,6 +8,8 @@
  * possible visibility states of a frame. @OnNonvisible is an enumeration that
  * allows callers to request a specific action when a frame transitions from
  * visible to nonvisible.
+ *
+ * IPC serializers are available in VisibilityIPC.h.
  */
 
 #ifndef mozilla_layout_generic_Visibility_h
@@ -18,21 +20,35 @@ namespace mozilla {
 // Visibility states for frames.
 enum class Visibility : uint8_t
 {
-  // Indicates that we're not tracking visibility for this frame.
+  // We're not tracking visibility for this frame.
   UNTRACKED,
 
-  // Indicates that the frame is probably nonvisible. Visible frames *may* be
+  // This frame is nonvisible - i.e., it was not within the displayport as of
-  // APPROXIMATELY_NONVISIBLE because approximate visibility is not updated
+  // the last paint (in which case it'd be IN_DISPLAYPORT) and our heuristics
-  // synchronously. Some truly nonvisible frames may be marked
+  // aren't telling us that it may become visible soon (in which case it'd be
-  // APPROXIMATELY_VISIBLE instead if our heuristics lead us to think they may
+  // MAY_BECOME_VISIBLE).
-  // be visible soon.
+  NONVISIBLE,
-  APPROXIMATELY_NONVISIBLE,
 
-  // Indicates that the frame is either visible now or is likely to be visible
+  // This frame is nonvisible now, but our heuristics tell us it may become
-  // soon according to our heuristics. As with APPROXIMATELY_NONVISIBLE, it's
+  // visible soon. These heuristics are updated on a relatively slow timer, so a
-  // important to note that approximately visibility is not updated
+  // frame being marked MAY_BECOME_VISIBLE does not imply any particular
-  // synchronously, so this information may be out of date.
+  // relationship between the frame and the displayport.
-  APPROXIMATELY_VISIBLE
+  MAY_BECOME_VISIBLE,
+
+  // This frame was within the displayport as of the last paint. That doesn't
+  // necessarily mean that the frame is visible - it may still lie outside the
+  // viewport - but it does mean that the user may scroll the frame into view
+  // asynchronously at any time (due to APZ), so for most purposes such a frame
+  // should be treated as truly visible.
+  IN_DISPLAYPORT
+};
+
+// The subset of the states in @Visibility which have a per-frame counter. This
+// is used in the implementation of visibility tracking.
+enum class VisibilityCounter : uint8_t
+{
+  MAY_BECOME_VISIBLE,
+  IN_DISPLAYPORT
 };
 
 // Requested actions when frames transition to the nonvisible state.

layout/generic/VisibilityIPC.h

@@ -0,0 +1,45 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Declares IPC serializers for the visibility-related types in Visibility.h.
+ * These are separated out to reduce the number of moz.build files that need to
+ * include chromium IPC headers, since Visibility.h is included from nsIFrame.h
+ * which is widely included.
+ */
+
+#ifndef mozilla_layout_generic_VisibilityIPC_h
+#define mozilla_layout_generic_VisibilityIPC_h
+
+#include "ipc/IPCMessageUtils.h"
+
+#include "Visibility.h"
+
+namespace IPC {
+
+template<>
+struct ParamTraits<mozilla::VisibilityCounter>
+{
+  typedef mozilla::VisibilityCounter paramType;
+
+  static void Write(Message* aMsg, const paramType& aParam)
+  {
+    WriteParam(aMsg, uint8_t(aParam));
+  }
+
+  static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
+  {
+    uint8_t valueAsByte;
+    if (ReadParam(aMsg, aIter, &valueAsByte)) {
+      *aResult = paramType(valueAsByte);
+      return true;
+    }
+    return false;
+  }
+};
+
+} // namespace IPC
+
+#endif // mozilla_layout_generic_VisibilityIPC_h

layout/generic/moz.build

@@ -98,6 +98,7 @@ EXPORTS += [
     'ScrollbarActivity.h',
     'ScrollSnap.h',
     'Visibility.h',
+    'VisibilityIPC.h',
 ]
 
 EXPORTS.mozilla += [

layout/generic/nsFlexContainerFrame.cpp

@@ -78,6 +78,89 @@ kAxisOrientationToSidesMap[eNumAxisOrientationTypes][eNumAxisEdges] = {
 
 // Helper structs / classes / methods
 // ==================================
+// Returns true iff the given nsStyleDisplay has display:-webkit-{inline-}-box.
+static inline bool
+IsDisplayValueLegacyBox(const nsStyleDisplay* aStyleDisp)
+{
+  return aStyleDisp->mDisplay == NS_STYLE_DISPLAY_WEBKIT_BOX ||
+    aStyleDisp->mDisplay == NS_STYLE_DISPLAY_WEBKIT_INLINE_BOX;
+}
+
+// Helper to check whether our nsFlexContainerFrame is emulating a legacy
+// -webkit-{inline-}box, in which case we should use legacy CSS properties
+// instead of the modern ones. The params are are the nsStyleDisplay and the
+// nsStyleContext associated with the nsFlexContainerFrame itself.
+static inline bool
+IsLegacyBox(const nsStyleDisplay* aStyleDisp,
+            nsStyleContext* aStyleContext)
+{
+  // Trivial case: just check "display" directly.
+  if (IsDisplayValueLegacyBox(aStyleDisp)) {
+    return true;
+  }
+
+  // If this frame is for a scrollable element, then it will actually have
+  // "display:block", and its *parent* will have the real flex-flavored display
+  // value. So in that case, check the parent to find out if we're legacy.
+  if (aStyleDisp->mDisplay == NS_STYLE_DISPLAY_BLOCK) {
+    nsStyleContext* parentStyleContext = aStyleContext->GetParent();
+    NS_ASSERTION(parentStyleContext &&
+                 aStyleContext->GetPseudo() == nsCSSAnonBoxes::scrolledContent,
+                 "The only way a nsFlexContainerFrame can have 'display:block' "
+                 "should be if it's the inner part of a scrollable element");
+    if (IsDisplayValueLegacyBox(parentStyleContext->StyleDisplay())) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+// Returns the "align-items" value that's equivalent to the legacy "box-align"
+// value in the given style struct.
+static uint8_t
+ConvertLegacyStyleToAlignItems(const nsStyleXUL* aStyleXUL)
+{
+  // -[moz|webkit]-box-align corresponds to modern "align-items"
+  switch (aStyleXUL->mBoxAlign) {
+    case NS_STYLE_BOX_ALIGN_STRETCH:
+      return NS_STYLE_ALIGN_STRETCH;
+    case NS_STYLE_BOX_ALIGN_START:
+      return NS_STYLE_ALIGN_FLEX_START;
+    case NS_STYLE_BOX_ALIGN_CENTER:
+      return NS_STYLE_ALIGN_CENTER;
+    case NS_STYLE_BOX_ALIGN_BASELINE:
+      return NS_STYLE_ALIGN_BASELINE;
+    case NS_STYLE_BOX_ALIGN_END:
+      return NS_STYLE_ALIGN_FLEX_END;
+  }
+
+  MOZ_ASSERT_UNREACHABLE("Unrecognized mBoxAlign enum value");
+  // Fall back to default value of "align-items" property:
+  return NS_STYLE_ALIGN_STRETCH;
+}
+
+// Returns the "justify-content" value that's equivalent to the legacy
+// "box-pack" value in the given style struct.
+static uint8_t
+ConvertLegacyStyleToJustifyContent(const nsStyleXUL* aStyleXUL)
+{
+  // -[moz|webkit]-box-pack corresponds to modern "justify-content"
+  switch (aStyleXUL->mBoxPack) {
+    case NS_STYLE_BOX_PACK_START:
+      return NS_STYLE_ALIGN_FLEX_START;
+    case NS_STYLE_BOX_PACK_CENTER:
+      return NS_STYLE_ALIGN_CENTER;
+    case NS_STYLE_BOX_PACK_END:
+      return NS_STYLE_ALIGN_FLEX_END;
+    case NS_STYLE_BOX_PACK_JUSTIFY:
+      return NS_STYLE_ALIGN_SPACE_BETWEEN;
+  }
+
+  MOZ_ASSERT_UNREACHABLE("Unrecognized mBoxPack enum value");
+  // Fall back to default value of "justify-content" property:
+  return NS_STYLE_ALIGN_FLEX_START;
+}
 
 // Indicates whether advancing along the given axis is equivalent to
 // increasing our X or Y position (as opposed to decreasing it).
@@ -156,7 +239,7 @@ PhysicalCoordFromFlexRelativeCoord(nscoord aFlexRelativeCoord,
 // Encapsulates our flex container's main & cross axes.
 class MOZ_STACK_CLASS nsFlexContainerFrame::FlexboxAxisTracker {
 public:
-  FlexboxAxisTracker(const nsStylePosition* aStylePosition,
+  FlexboxAxisTracker(const nsFlexContainerFrame* aFlexContainer,
                      const WritingMode& aWM);
 
   // Accessors:
@@ -287,6 +370,15 @@ private:
   FlexboxAxisTracker(const FlexboxAxisTracker&) = delete;
   FlexboxAxisTracker& operator=(const FlexboxAxisTracker&) = delete;
 
+  // Helpers for constructor which determine the orientation of our axes, based
+  // on legacy box properties (-webkit-box-orient, -webkit-box-direction) or
+  // modern flexbox properties (flex-direction, flex-wrap) depending on whether
+  // the flex container is a "legacy box" (as determined by IsLegacyBox).
+  void InitAxesFromLegacyProps(const nsFlexContainerFrame* aFlexContainer,
+                               const WritingMode& aWM);
+  void InitAxesFromModernProps(const nsFlexContainerFrame* aFlexContainer,
+                               const WritingMode& aWM);
+
   // XXXdholbert [BEGIN DEPRECATED]
   AxisOrientationType mMainAxis;
   AxisOrientationType mCrossAxis;
@@ -890,6 +982,29 @@ BuildStrutInfoFromCollapsedItems(const FlexLine* aFirstLine,
   }
 }
 
+// Convenience function to get either the "order" or the "box-ordinal-group"
+// property-value for a flex item (depending on whether the container is a
+// modern flex container or a legacy box).
+static int32_t
+GetOrderOrBoxOrdinalGroup(nsIFrame* aFlexItem, bool aIsLegacyBox)
+{
+  if (aIsLegacyBox) {
+    // We'll be using mBoxOrdinal, which has type uint32_t. However, the modern
+    // 'order' property (whose functionality we're co-opting) has type int32_t.
+    // So: if we happen to have a uint32_t value that's greater than INT32_MAX,
+    // we clamp it rather than letting it overflow. Chances are, this is just
+    // an author using BIG_VALUE anyway, so the clamped value should be fine.
+    // (particularly since sufficiently-huge values are busted in Chrome/WebKit
+    // per https://bugs.chromium.org/p/chromium/issues/detail?id=599645 )
+    uint32_t clampedBoxOrdinal = std::min(aFlexItem->StyleXUL()->mBoxOrdinal,
+                                          static_cast<uint32_t>(INT32_MAX));
+    return static_cast<int32_t>(clampedBoxOrdinal);
+  }
+
+  // Normal case: just use modern 'order' property.
+  return aFlexItem->StylePosition()->mOrder;
+}
+
 // Helper-function to find the first non-anonymous-box descendent of aFrame.
 static nsIFrame*
 GetFirstNonAnonBoxDescendant(nsIFrame* aFrame)
@@ -954,6 +1069,11 @@ IsOrderLEQWithDOMFallback(nsIFrame* aFrame1,
 {
   MOZ_ASSERT(aFrame1->IsFlexItem() && aFrame2->IsFlexItem(),
              "this method only intended for comparing flex items");
+  MOZ_ASSERT(aFrame1->GetParent() == aFrame2->GetParent(),
+             "this method only intended for comparing siblings");
+  nsStyleContext* parentFrameSC = aFrame1->GetParent()->StyleContext();
+  bool isInLegacyBox = IsLegacyBox(parentFrameSC->StyleDisplay(),
+                                   parentFrameSC);
 
   if (aFrame1 == aFrame2) {
     // Anything is trivially LEQ itself, so we return "true" here... but it's
@@ -967,8 +1087,8 @@ IsOrderLEQWithDOMFallback(nsIFrame* aFrame1,
     nsIFrame* aRealFrame1 = nsPlaceholderFrame::GetRealFrameFor(aFrame1);
     nsIFrame* aRealFrame2 = nsPlaceholderFrame::GetRealFrameFor(aFrame2);
 
-    int32_t order1 = aRealFrame1->StylePosition()->mOrder;
+    int32_t order1 = GetOrderOrBoxOrdinalGroup(aRealFrame1, isInLegacyBox);
-    int32_t order2 = aRealFrame2->StylePosition()->mOrder;
+    int32_t order2 = GetOrderOrBoxOrdinalGroup(aRealFrame2, isInLegacyBox);
 
     if (order1 != order2) {
       return order1 < order2;
@@ -1035,13 +1155,18 @@ IsOrderLEQ(nsIFrame* aFrame1,
 {
   MOZ_ASSERT(aFrame1->IsFlexItem() && aFrame2->IsFlexItem(),
              "this method only intended for comparing flex items");
+  MOZ_ASSERT(aFrame1->GetParent() == aFrame2->GetParent(),
+             "this method only intended for comparing siblings");
+  nsStyleContext* parentFrameSC = aFrame1->GetParent()->StyleContext();
+  bool isInLegacyBox = IsLegacyBox(parentFrameSC->StyleDisplay(),
+                                   parentFrameSC);
 
   // If we've got a placeholder frame, use its out-of-flow frame's 'order' val.
   nsIFrame* aRealFrame1 = nsPlaceholderFrame::GetRealFrameFor(aFrame1);
   nsIFrame* aRealFrame2 = nsPlaceholderFrame::GetRealFrameFor(aFrame2);
 
-  int32_t order1 = aRealFrame1->StylePosition()->mOrder;
+  int32_t order1 = GetOrderOrBoxOrdinalGroup(aRealFrame1, isInLegacyBox);
-  int32_t order2 = aRealFrame2->StylePosition()->mOrder;
+  int32_t order2 = GetOrderOrBoxOrdinalGroup(aRealFrame2, isInLegacyBox);
 
   return order1 <= order2;
 }
@@ -1049,7 +1174,7 @@ IsOrderLEQ(nsIFrame* aFrame1,
 bool
 nsFlexContainerFrame::IsHorizontal()
 {
-  const FlexboxAxisTracker axisTracker(StylePosition(), GetWritingMode());
+  const FlexboxAxisTracker axisTracker(this, GetWritingMode());
   return axisTracker.IsMainAxisHorizontal();
 }
 
@@ -1069,9 +1194,15 @@ nsFlexContainerFrame::GenerateFlexItemForChild(
 
   // FLEX GROW & SHRINK WEIGHTS
   // --------------------------
-  const nsStylePosition* stylePos = aChildFrame->StylePosition();
+  float flexGrow, flexShrink;
-  float flexGrow   = stylePos->mFlexGrow;
+  if (IsLegacyBox(aParentReflowState.mStyleDisplay, mStyleContext)) {
-  float flexShrink = stylePos->mFlexShrink;
+    flexGrow = flexShrink = aChildFrame->StyleXUL()->mBoxFlex;
+  } else {
+    const nsStylePosition* stylePos = aChildFrame->StylePosition();
+    flexGrow   = stylePos->mFlexGrow;
+    flexShrink = stylePos->mFlexShrink;
+  }
+
   WritingMode childWM = childRS.GetWritingMode();
 
   // MAIN SIZES (flex base size, min/max size)
@@ -1576,14 +1707,28 @@ FlexItem::FlexItem(nsHTMLReflowState& aFlexItemReflowState,
   MOZ_ASSERT(!(mFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW),
              "out-of-flow frames should not be treated as flex items");
 
-  mAlignSelf = aFlexItemReflowState.mStylePosition->ComputedAlignSelf(
+  const nsHTMLReflowState* containerRS = aFlexItemReflowState.parentReflowState;
-                 mFrame->StyleContext()->GetParent());
+  if (IsLegacyBox(containerRS->mStyleDisplay,
-  if (MOZ_LIKELY(mAlignSelf == NS_STYLE_ALIGN_NORMAL)) {
+                  containerRS->frame->StyleContext())) {
-    mAlignSelf = NS_STYLE_ALIGN_STRETCH;
+    // For -webkit-box/-webkit-inline-box, we need to:
-  }
+    // (1) Use "-webkit-box-align" instead of "align-items" to determine the
+    //     container's cross-axis alignment behavior.
+    // (2) Suppress the ability for flex items to override that with their own
+    //     cross-axis alignment. (The legacy box model doesn't support this.)
+    // So, each FlexItem simply copies the container's converted "align-items"
+    // value and disregards their own "align-self" property.
+    const nsStyleXUL* containerStyleXUL = containerRS->frame->StyleXUL();
+    mAlignSelf = ConvertLegacyStyleToAlignItems(containerStyleXUL);
+  } else {
+    mAlignSelf = aFlexItemReflowState.mStylePosition->ComputedAlignSelf(
+                   mFrame->StyleContext()->GetParent());
+    if (MOZ_LIKELY(mAlignSelf == NS_STYLE_ALIGN_NORMAL)) {
+      mAlignSelf = NS_STYLE_ALIGN_STRETCH;
+    }
 
-  // XXX strip off the <overflow-position> bit until we implement that
+    // XXX strip off the <overflow-position> bit until we implement that
-  mAlignSelf &= ~NS_STYLE_ALIGN_FLAG_BITS;
+    mAlignSelf &= ~NS_STYLE_ALIGN_FLAG_BITS;
+  }
 
   SetFlexBaseSizeAndMainSize(aFlexBaseSize);
   CheckForMinSizeAuto(aFlexItemReflowState, aAxisTracker);
@@ -1940,7 +2085,7 @@ public:
 
 NS_QUERYFRAME_HEAD(nsFlexContainerFrame)
   NS_QUERYFRAME_ENTRY(nsFlexContainerFrame)
-NS_QUERYFRAME_TAIL_INHERITING(nsFlexContainerFrameSuper)
+NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
 
 NS_IMPL_FRAMEARENA_HELPERS(nsFlexContainerFrame)
 
@@ -3058,12 +3203,92 @@ BlockDirToAxisOrientation(WritingMode::BlockDir aBlockDir)
   return eAxis_TB; // in case of unforseen error, assume English TTB block-flow
 }
 
-FlexboxAxisTracker::FlexboxAxisTracker(const nsStylePosition* aStylePosition,
+FlexboxAxisTracker::FlexboxAxisTracker(
-                                       const WritingMode& aWM)
+  const nsFlexContainerFrame* aFlexContainer,
+  const WritingMode& aWM)
   : mWM(aWM),
     mAreAxesInternallyReversed(false)
 {
-  uint32_t flexDirection = aStylePosition->mFlexDirection;
+  if (IsLegacyBox(aFlexContainer->StyleDisplay(),
+                  aFlexContainer->StyleContext())) {
+    InitAxesFromLegacyProps(aFlexContainer, aWM);
+  } else {
+    InitAxesFromModernProps(aFlexContainer, aWM);
+  }
+
+  // Master switch to enable/disable bug 983427's code for reversing our axes
+  // and reversing some logic, to avoid reflowing children in bottom-to-top
+  // order. (This switch can be removed eventually, but for now, it allows
+  // this special-case code path to be compared against the normal code path.)
+  static bool sPreventBottomToTopChildOrdering = true;
+
+  if (sPreventBottomToTopChildOrdering) {
+    // If either axis is bottom-to-top, we flip both axes (and set a flag
+    // so that we can flip some logic to make the reversal transparent).
+    if (eAxis_BT == mMainAxis || eAxis_BT == mCrossAxis) {
+      mMainAxis = GetReverseAxis(mMainAxis);
+      mCrossAxis = GetReverseAxis(mCrossAxis);
+      mAreAxesInternallyReversed = true;
+      mIsMainAxisReversed = !mIsMainAxisReversed;
+      mIsCrossAxisReversed = !mIsCrossAxisReversed;
+    }
+  }
+}
+
+void
+FlexboxAxisTracker::InitAxesFromLegacyProps(
+  const nsFlexContainerFrame* aFlexContainer,
+  const WritingMode& aWM)
+{
+  const nsStyleXUL* styleXUL = aFlexContainer->StyleXUL();
+
+  const bool boxOrientIsVertical = (styleXUL->mBoxOrient ==
+                                    NS_STYLE_BOX_ORIENT_VERTICAL);
+  const bool wmIsVertical = aWM.IsVertical();
+
+  // If box-orient agrees with our writing-mode, then we're "row-oriented"
+  // (i.e. the flexbox main axis is the same as our writing mode's inline
+  // direction).  Otherwise, we're column-oriented (i.e. the flexbox's main
+  // axis is perpendicular to the writing-mode's inline direction).
+  mIsRowOriented = (boxOrientIsVertical == wmIsVertical);
+
+  // XXXdholbert BEGIN CODE TO SET DEPRECATED MEMBER-VARS
+  if (boxOrientIsVertical) {
+    mMainAxis = eAxis_TB;
+    mCrossAxis = eAxis_LR;
+  } else {
+    mMainAxis = eAxis_LR;
+    mCrossAxis = eAxis_TB;
+  }
+  // "direction: rtl" (in a horizontal -webkit-box) reverses the main axis.
+  // (Note this we don't toggle "mIsMainAxisReversed" for this condition,
+  // because the main axis will still match aWM's inline direction.)
+  if (aWM.IsBidiLTR()) {
+    mMainAxis = GetReverseAxis(mMainAxis);
+  }
+  // XXXdholbert END CODE TO SET DEPRECATED MEMBER-VARS
+
+  // Legacy flexbox can use "-webkit-box-direction: reverse" to reverse the
+  // main axis (so it runs in the reverse direction of the inline axis):
+  if (styleXUL->mBoxDirection == NS_STYLE_BOX_DIRECTION_REVERSE) {
+    mMainAxis = GetReverseAxis(mMainAxis);
+    mIsMainAxisReversed = true;
+  } else {
+    mIsMainAxisReversed = false;
+  }
+
+  // Legacy flexbox does not support reversing the cross axis -- it has no
+  // equivalent of modern flexbox's "flex-wrap: wrap-reverse".
+  mIsCrossAxisReversed = false;
+}
+
+void
+FlexboxAxisTracker::InitAxesFromModernProps(
+  const nsFlexContainerFrame* aFlexContainer,
+  const WritingMode& aWM)
+{
+  const nsStylePosition* stylePos = aFlexContainer->StylePosition();
+  uint32_t flexDirection = stylePos->mFlexDirection;
 
   // Inline dimension ("start-to-end"):
   // (NOTE: I'm intentionally not calling these "inlineAxis"/"blockAxis", since
@@ -3111,30 +3336,12 @@ FlexboxAxisTracker::FlexboxAxisTracker(const nsStylePosition* aStylePosition,
   }
 
   // "flex-wrap: wrap-reverse" reverses our cross axis.
-  if (aStylePosition->mFlexWrap == NS_STYLE_FLEX_WRAP_WRAP_REVERSE) {
+  if (stylePos->mFlexWrap == NS_STYLE_FLEX_WRAP_WRAP_REVERSE) {
     mCrossAxis = GetReverseAxis(mCrossAxis);
     mIsCrossAxisReversed = true;
   } else {
     mIsCrossAxisReversed = false;
   }
-
-  // Master switch to enable/disable bug 983427's code for reversing our axes
-  // and reversing some logic, to avoid reflowing children in bottom-to-top
-  // order. (This switch can be removed eventually, but for now, it allows
-  // this special-case code path to be compared against the normal code path.)
-  static bool sPreventBottomToTopChildOrdering = true;
-
-  if (sPreventBottomToTopChildOrdering) {
-    // If either axis is bottom-to-top, we flip both axes (and set a flag
-    // so that we can flip some logic to make the reversal transparent).
-    if (eAxis_BT == mMainAxis || eAxis_BT == mCrossAxis) {
-      mMainAxis = GetReverseAxis(mMainAxis);
-      mCrossAxis = GetReverseAxis(mCrossAxis);
-      mAreAxesInternallyReversed = true;
-      mIsMainAxisReversed = !mIsMainAxisReversed;
-      mIsCrossAxisReversed = !mIsCrossAxisReversed;
-    }
-  }
 }
 
 // Allocates a new FlexLine, adds it to the given LinkedList (at the front or
@@ -3647,8 +3854,7 @@ nsFlexContainerFrame::Reflow(nsPresContext*           aPresContext,
     SortChildrenIfNeeded<IsOrderLEQWithDOMFallback>();
   }
 
-  const FlexboxAxisTracker axisTracker(aReflowState.mStylePosition,
+  const FlexboxAxisTracker axisTracker(this, aReflowState.GetWritingMode());
-                                       aReflowState.GetWritingMode());
 
   // If we're being fragmented into a constrained BSize, then subtract off
   // borderpadding BStart from that constrained BSize, to get the available
@@ -3858,11 +4064,14 @@ nsFlexContainerFrame::DoFlexLayout(nsPresContext*           aPresContext,
     }
   }
 
-  for (FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
+  const auto justifyContent = IsLegacyBox(aReflowState.mStyleDisplay,
+                                          mStyleContext) ?
+    ConvertLegacyStyleToJustifyContent(StyleXUL()) :
+    aReflowState.mStylePosition->ComputedJustifyContent();
 
+  for (FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
     // Main-Axis Alignment - Flexbox spec section 9.5
     // ==============================================
-    auto justifyContent = aReflowState.mStylePosition->ComputedJustifyContent();
     line->PositionItemsInMainAxis(justifyContent,
                                   aContentBoxMainSize,
                                   aAxisTracker);
@@ -4069,6 +4278,7 @@ nsFlexContainerFrame::MoveFlexItemToFinalPosition(
                                               logicalOffsets, &aFramePos,
                                               aContainerSize);
   aItem.Frame()->SetPosition(outerWM, aFramePos, aContainerSize);
+  PositionFrameView(aItem.Frame());
   PositionChildViews(aItem.Frame());
 }
 
@@ -4186,7 +4396,7 @@ nsFlexContainerFrame::GetMinISize(nsRenderingContext* aRenderingContext)
   DISPLAY_MIN_WIDTH(this, minWidth);
 
   const nsStylePosition* stylePos = StylePosition();
-  const FlexboxAxisTracker axisTracker(stylePos, GetWritingMode());
+  const FlexboxAxisTracker axisTracker(this, GetWritingMode());
 
   for (nsIFrame* childFrame : mFrames) {
     nscoord childMinWidth =
@@ -4217,7 +4427,7 @@ nsFlexContainerFrame::GetPrefISize(nsRenderingContext* aRenderingContext)
   // Whenever anything happens that might change it, set it to
   // NS_INTRINSIC_WIDTH_UNKNOWN (like nsBlockFrame::MarkIntrinsicISizesDirty
   // does)
-  const FlexboxAxisTracker axisTracker(StylePosition(), GetWritingMode());
+  const FlexboxAxisTracker axisTracker(this, GetWritingMode());
 
   for (nsIFrame* childFrame : mFrames) {
     nscoord childPrefWidth =

layout/generic/nsFlexContainerFrame.h

@@ -5,7 +5,7 @@
  * version 2.0 (the "License"). You can obtain a copy of the License at
  * http://mozilla.org/MPL/2.0/. */
 
-/* rendering object for CSS "display: flex" */
+/* rendering object for CSS "display: flex" and "display: -webkit-box" */
 
 #ifndef nsFlexContainerFrame_h___
 #define nsFlexContainerFrame_h___
@@ -20,9 +20,27 @@ class LogicalPoint;
 nsContainerFrame* NS_NewFlexContainerFrame(nsIPresShell* aPresShell,
                                            nsStyleContext* aContext);
 
-typedef nsContainerFrame nsFlexContainerFrameSuper;
 
-class nsFlexContainerFrame : public nsFlexContainerFrameSuper {
+/**
+ * This is the rendering object used for laying out elements with
+ * "display: flex" or "display: inline-flex".
+ *
+ * We also use this class for elements with "display: -webkit-box" or
+ * "display: -webkit-inline-box" (but not "-moz-box" / "-moz-inline-box" --
+ * those are rendered with old-school XUL frame classes).
+ *
+ * Note: we represent the -webkit-box family of properties (-webkit-box-orient,
+ * -webkit-box-flex, etc.) as aliases for their -moz equivalents.  And for
+ * -webkit-{inline-}box containers, nsFlexContainerFrame will honor those
+ * "legacy" properties for alignment/flexibility/etc. *instead of* honoring the
+ * modern flexbox & alignment properties.  For brevity, many comments in
+ * nsFlexContainerFrame.cpp simply refer to these properties using their
+ * "-webkit" versions, since we're mostly expecting to encounter them in that
+ * form. (Technically, the "-moz" versions of these properties *can* influence
+ * layout here as well (since that's what the -webkit versions are aliased to)
+ * -- but only inside of a "display:-webkit-{inline-}box" container.)
+ */
+class nsFlexContainerFrame : public nsContainerFrame {
 public:
   NS_DECL_FRAMEARENA_HELPERS
   NS_DECL_QUERYFRAME_TARGET(nsFlexContainerFrame)
@@ -62,8 +80,8 @@ public:
 
 protected:
   // Protected constructor & destructor
-  explicit nsFlexContainerFrame(nsStyleContext* aContext) :
+  explicit nsFlexContainerFrame(nsStyleContext* aContext)
-    nsFlexContainerFrameSuper(aContext)
+    : nsContainerFrame(aContext)
   {}
   virtual ~nsFlexContainerFrame();
 

layout/generic/nsFrame.cpp

@@ -414,7 +414,7 @@ nsFrame::~nsFrame()
 {
   MOZ_COUNT_DTOR(nsFrame);
 
-  MOZ_ASSERT(GetVisibility() != Visibility::APPROXIMATELY_VISIBLE,
+  MOZ_ASSERT(!IsVisibleOrMayBecomeVisibleSoon(),
              "Visible nsFrame is being destroyed");
 
   NS_IF_RELEASE(mContent);
@@ -553,7 +553,7 @@ nsFrame::Init(nsIContent*       aContent,
 
     if (HasAnyStateBits(NS_FRAME_IN_POPUP) && TrackingVisibility()) {
       // Assume all frames in popups are visible.
-      IncApproximateVisibleCount();
+      IncVisibilityCount(VisibilityCounter::IN_DISPLAYPORT);
     }
   }
   const nsStyleDisplay *disp = StyleDisplay();
@@ -606,7 +606,7 @@ nsFrame::Init(nsIContent*       aContent,
 
   if (PresContext()->PresShell()->AssumeAllFramesVisible() &&
       TrackingVisibility()) {
-    IncApproximateVisibleCount();
+    IncVisibilityCount(VisibilityCounter::IN_DISPLAYPORT);
   }
 
   DidSetStyleContext(nullptr);
@@ -733,8 +733,8 @@ nsFrame::DestroyFrom(nsIFrame* aDestructRoot)
   // frame reconstruction induced by style changes.
   DisableVisibilityTracking();
 
-  // Ensure that we're not in the approximately visible list anymore.
+  // Ensure that we're not in the visible list anymore.
-  PresContext()->GetPresShell()->RemoveFrameFromApproximatelyVisibleList(this);
+  PresContext()->GetPresShell()->MarkFrameNonvisible(this);
 
   shell->NotifyDestroyingFrame(this);
 
@@ -1476,6 +1476,18 @@ nsIFrame::GetCrossDocChildLists(nsTArray<ChildList>* aLists)
   GetChildLists(aLists);
 }
 
+static Visibility
+VisibilityStateAsVisibility(const nsIFrame::VisibilityState& aState)
+{
+  if (aState.mInDisplayPortCounter > 0) {
+    return Visibility::IN_DISPLAYPORT;  // Takes priority over MAY_BECOME_VISIBLE.
+  }
+  if (aState.mApproximateCounter > 0) {
+    return Visibility::MAY_BECOME_VISIBLE;
+  }
+  return Visibility::NONVISIBLE;
+}
+
 Visibility
 nsIFrame::GetVisibility() const
 {
@@ -1485,14 +1497,12 @@ nsIFrame::GetVisibility() const
 
   bool isSet = false;
   FrameProperties props = Properties();
-  uint32_t visibleCount = props.Get(VisibilityStateProperty(), &isSet);
+  VisibilityState state = props.Get(VisibilityStateProperty(), &isSet);
 
   MOZ_ASSERT(isSet, "Should have a VisibilityStateProperty value "
                     "if NS_FRAME_VISIBILITY_IS_TRACKED is set");
 
-  return visibleCount > 0
+  return VisibilityStateAsVisibility(state);
-       ? Visibility::APPROXIMATELY_VISIBLE
-       : Visibility::APPROXIMATELY_NONVISIBLE;
 }
 
 void
@@ -1504,7 +1514,7 @@ nsIFrame::UpdateVisibilitySynchronously()
   }
 
   if (presShell->AssumeAllFramesVisible()) {
-    presShell->EnsureFrameInApproximatelyVisibleList(this);
+    presShell->MarkFrameVisibleInDisplayPort(this);
     return;
   }
 
@@ -1545,9 +1555,9 @@ nsIFrame::UpdateVisibilitySynchronously()
   }
 
   if (visible) {
-    presShell->EnsureFrameInApproximatelyVisibleList(this);
+    presShell->MarkFrameVisibleInDisplayPort(this);
   } else {
-    presShell->RemoveFrameFromApproximatelyVisibleList(this);
+    presShell->MarkFrameNonvisible(this);
   }
 }
 
@@ -1566,7 +1576,7 @@ nsIFrame::EnableVisibilityTracking()
   // Add the state bit so we know to track visibility for this frame, and
   // initialize the frame property.
   AddStateBits(NS_FRAME_VISIBILITY_IS_TRACKED);
-  props.Set(VisibilityStateProperty(), 0);
+  props.Set(VisibilityStateProperty(), VisibilityState{0, 0});
 
   nsIPresShell* presShell = PresContext()->PresShell();
   if (!presShell) {
@@ -1589,66 +1599,87 @@ nsIFrame::DisableVisibilityTracking()
 
   bool isSet = false;
   FrameProperties props = Properties();
-  uint32_t visibleCount = props.Remove(VisibilityStateProperty(), &isSet);
+  VisibilityState state = props.Remove(VisibilityStateProperty(), &isSet);
 
   MOZ_ASSERT(isSet, "Should have a VisibilityStateProperty value "
                     "if NS_FRAME_VISIBILITY_IS_TRACKED is set");
 
   RemoveStateBits(NS_FRAME_VISIBILITY_IS_TRACKED);
 
-  if (visibleCount == 0) {
+  Visibility previousVisibility = VisibilityStateAsVisibility(state);
-    return;  // We were nonvisible.
+  if (previousVisibility == Visibility::NONVISIBLE) {
+    return;  // We were already nonvisible.
   }
 
   // We were visible, so send an OnVisibilityChange() notification.
-  OnVisibilityChange(Visibility::APPROXIMATELY_NONVISIBLE);
+  OnVisibilityChange(Visibility::NONVISIBLE);
 }
 
 void
-nsIFrame::DecApproximateVisibleCount(Maybe<OnNonvisible> aNonvisibleAction
+nsIFrame::DecVisibilityCount(VisibilityCounter aCounter,
-                                       /* = Nothing() */)
+                             Maybe<OnNonvisible> aNonvisibleAction /* = Nothing() */)
 {
   MOZ_ASSERT(GetStateBits() & NS_FRAME_VISIBILITY_IS_TRACKED);
 
   bool isSet = false;
   FrameProperties props = Properties();
-  uint32_t visibleCount = props.Get(VisibilityStateProperty(), &isSet);
+  VisibilityState state = props.Get(VisibilityStateProperty(), &isSet);
 
   MOZ_ASSERT(isSet, "Should have a VisibilityStateProperty value "
                     "if NS_FRAME_VISIBILITY_IS_TRACKED is set");
-  MOZ_ASSERT(visibleCount > 0, "Frame is already nonvisible and we're "
+  MOZ_ASSERT_IF(aCounter == VisibilityCounter::MAY_BECOME_VISIBLE,
-                               "decrementing its visible count?");
+                state.mApproximateCounter > 0);
+  MOZ_ASSERT_IF(aCounter == VisibilityCounter::IN_DISPLAYPORT,
+                state.mInDisplayPortCounter > 0);
 
-  visibleCount--;
+  Visibility previousVisibility = VisibilityStateAsVisibility(state);
-  props.Set(VisibilityStateProperty(), visibleCount);
+
-  if (visibleCount > 0) {
+  if (aCounter == VisibilityCounter::MAY_BECOME_VISIBLE) {
-    return;
+    state.mApproximateCounter--;
+  } else {
+    state.mInDisplayPortCounter--;
   }
 
-  // We just became nonvisible, so send an OnVisibilityChange() notification.
+  props.Set(VisibilityStateProperty(), state);
-  OnVisibilityChange(Visibility::APPROXIMATELY_NONVISIBLE, aNonvisibleAction);
+
+  Visibility newVisibility = VisibilityStateAsVisibility(state);
+  if (newVisibility == previousVisibility) {
+    return;  // Nothing changed.
+  }
+
+  // Our visibility just changed, so send an OnVisibilityChange() notification.
+  OnVisibilityChange(newVisibility, aNonvisibleAction);
 }
 
 void
-nsIFrame::IncApproximateVisibleCount()
+nsIFrame::IncVisibilityCount(VisibilityCounter aCounter)
 {
   MOZ_ASSERT(GetStateBits() & NS_FRAME_VISIBILITY_IS_TRACKED);
 
   bool isSet = false;
   FrameProperties props = Properties();
-  uint32_t visibleCount = props.Get(VisibilityStateProperty(), &isSet);
+  VisibilityState state = props.Get(VisibilityStateProperty(), &isSet);
 
   MOZ_ASSERT(isSet, "Should have a VisibilityStateProperty value "
                     "if NS_FRAME_VISIBILITY_IS_TRACKED is set");
 
-  visibleCount++;
+  Visibility previousVisibility = VisibilityStateAsVisibility(state);
-  props.Set(VisibilityStateProperty(), visibleCount);
+
-  if (visibleCount > 1) {
+  if (aCounter == VisibilityCounter::MAY_BECOME_VISIBLE) {
-    return;
+    state.mApproximateCounter++;
+  } else {
+    state.mInDisplayPortCounter++;
   }
 
-  // We just became visible, so send an OnVisibilityChange() notification.
+  props.Set(VisibilityStateProperty(), state);
-  OnVisibilityChange(Visibility::APPROXIMATELY_VISIBLE);
+
+  Visibility newVisibility = VisibilityStateAsVisibility(state);
+  if (newVisibility == previousVisibility) {
+    return;  // Nothing changed.
+  }
+
+  // Our visibility just changed, so send an OnVisibilityChange() notification.
+  OnVisibilityChange(newVisibility);
 }
 
 void
@@ -2683,6 +2714,14 @@ nsIFrame::BuildDisplayListForChild(nsDisplayListBuilder*   aBuilder,
       !PresContext()->GetTheme()->WidgetIsContainer(ourDisp->mAppearance))
     return;
 
+  // Since we're now sure that we're adding this frame to the display list
+  // (which means we're painting it, modulo occlusion), mark it as visible
+  // within the displayport.
+  if (aBuilder->IsPaintingToWindow() && child->TrackingVisibility()) {
+    nsIPresShell* shell = child->PresContext()->PresShell();
+    shell->MarkFrameVisibleInDisplayPort(child);
+  }
+
   // Child is composited if it's transformed, partially transparent, or has
   // SVG effects or a blend mode..
   const nsStyleDisplay* disp = child->StyleDisplay();
@@ -9166,7 +9205,7 @@ nsIFrame::AddInPopupStateBitToDescendants(nsIFrame* aFrame)
   if (!aFrame->HasAnyStateBits(NS_FRAME_IN_POPUP) &&
       aFrame->TrackingVisibility()) {
     // Assume all frames in popups are visible.
-    aFrame->IncApproximateVisibleCount();
+    aFrame->IncVisibilityCount(VisibilityCounter::IN_DISPLAYPORT);
   }
 
   aFrame->AddStateBits(NS_FRAME_IN_POPUP);
@@ -9196,7 +9235,7 @@ nsIFrame::RemoveInPopupStateBitFromDescendants(nsIFrame* aFrame)
   if (aFrame->TrackingVisibility()) {
     // We assume all frames in popups are visible, so this decrement balances
     // out the increment in AddInPopupStateBitToDescendants above.
-    aFrame->DecApproximateVisibleCount();
+    aFrame->DecVisibilityCount(VisibilityCounter::IN_DISPLAYPORT);
   }
 
   AutoTArray<nsIFrame::ChildList,4> childListArray;

layout/generic/nsIFrame.h

@@ -424,6 +424,7 @@ public:
   template<typename T=void>
   using PropertyDescriptor = const mozilla::FramePropertyDescriptor<T>*;
   using Visibility = mozilla::Visibility;
+  using VisibilityCounter = mozilla::VisibilityCounter;
 
   typedef mozilla::FrameProperties FrameProperties;
   typedef mozilla::layers::Layer Layer;
@@ -1106,6 +1107,15 @@ public:
   /// for the possible return values and their meanings.
   Visibility GetVisibility() const;
 
+  /// @return true if this frame is either in the displayport now or may
+  /// become visible soon.
+  bool IsVisibleOrMayBecomeVisibleSoon() const
+  {
+    Visibility visibility = GetVisibility();
+    return visibility == Visibility::MAY_BECOME_VISIBLE ||
+           visibility == Visibility::IN_DISPLAYPORT;
+  }
+
   /// Update the visibility state of this frame synchronously.
   /// XXX(seth): Avoid using this method; we should be relying on the refresh
   /// driver for visibility updates. This method, which replaces
@@ -1114,11 +1124,17 @@ public:
   /// the old image visibility code.
   void UpdateVisibilitySynchronously();
 
-  // A frame property which stores the visibility state of this frame. Right
+  struct VisibilityState
-  // now that consists of an approximate visibility counter represented as a
+  {
-  // uint32_t. When the visibility of this frame is not being tracked, this
+    unsigned int mApproximateCounter : 16;
-  // property is absent.
+    unsigned int mInDisplayPortCounter : 16;
-  NS_DECLARE_FRAME_PROPERTY_SMALL_VALUE(VisibilityStateProperty, uint32_t);
+  };
+
+  // A frame property which stores the visibility state of this frame, which
+  // consists of a VisibilityState value that stores counters for each type of
+  // visibility we track. When the visibility of this frame is not being
+  // tracked, this property is absent.
+  NS_DECLARE_FRAME_PROPERTY_SMALL_VALUE(VisibilityStateProperty, VisibilityState);
 
 protected:
 
@@ -1163,12 +1179,19 @@ public:
   ///////////////////////////////////////////////////////////////////////////////
 
   /**
-   * We track the approximate visibility of frames using a counter; if it's
+   * We track the visibility of frames using counters; if any of the counters
-   * non-zero, then the frame is considered visible. Using a counter allows us
+   * are non-zero, then the frame is considered visible. Using counters allows
-   * to account for situations where the frame may be visible in more than one
+   * us to account for situations where the frame may be visible in more than
-   * place (for example, via -moz-element), and it simplifies the
+   * one place (for example, via -moz-element), and it simplifies the
    * implementation of our approximate visibility tracking algorithms.
    *
+   * There are two visibility counters for each frame: the approximate counter
+   * (which is based on our heuristics for which frames may become visible
+   * "soon"), and the in-displayport counter (which records if the frame was
+   * within the displayport at the last paint).
+   *
+   *
+   * @param aCounter          Which counter to increment or decrement.
    * @param aNonvisibleAction A requested action if the frame has become
    *                          nonvisible. If Nothing(), no action is
    *                          requested. If DISCARD_IMAGES is specified, the
@@ -1176,8 +1199,9 @@ public:
    *                          associated with to discard their surfaces if
    *                          possible.
    */
-  void DecApproximateVisibleCount(Maybe<OnNonvisible> aNonvisibleAction = Nothing());
+  void DecVisibilityCount(VisibilityCounter aCounter,
-  void IncApproximateVisibleCount();
+                          Maybe<OnNonvisible> aNonvisibleAction = Nothing());
+  void IncVisibilityCount(VisibilityCounter aCounter);
 
 
   /**

layout/generic/nsImageFrame.cpp

@@ -136,7 +136,7 @@ NS_IMPL_FRAMEARENA_HELPERS(nsImageFrame)
 
 
 nsImageFrame::nsImageFrame(nsStyleContext* aContext) :
-  ImageFrameSuper(aContext),
+  nsAtomicContainerFrame(aContext),
   mComputedSize(0, 0),
   mIntrinsicRatio(0, 0),
   mDisplayingIcon(false),
@@ -158,7 +158,7 @@ nsImageFrame::~nsImageFrame()
 
 NS_QUERYFRAME_HEAD(nsImageFrame)
   NS_QUERYFRAME_ENTRY(nsImageFrame)
-NS_QUERYFRAME_TAIL_INHERITING(ImageFrameSuper)
+NS_QUERYFRAME_TAIL_INHERITING(nsAtomicContainerFrame)
 
 #ifdef ACCESSIBILITY
 a11y::AccType
@@ -222,13 +222,13 @@ nsImageFrame::DestroyFrom(nsIFrame* aDestructRoot)
   if (mDisplayingIcon)
     gIconLoad->RemoveIconObserver(this);
 
-  ImageFrameSuper::DestroyFrom(aDestructRoot);
+  nsAtomicContainerFrame::DestroyFrom(aDestructRoot);
 }
 
 void
 nsImageFrame::DidSetStyleContext(nsStyleContext* aOldStyleContext)
 {
-  ImageFrameSuper::DidSetStyleContext(aOldStyleContext);
+  nsAtomicContainerFrame::DidSetStyleContext(aOldStyleContext);
 
   if (!mImage) {
     // We'll pick this change up whenever we do get an image.
@@ -258,7 +258,7 @@ nsImageFrame::Init(nsIContent*       aContent,
                    nsContainerFrame* aParent,
                    nsIFrame*         aPrevInFlow)
 {
-  ImageFrameSuper::Init(aContent, aParent, aPrevInFlow);
+  nsAtomicContainerFrame::Init(aContent, aParent, aPrevInFlow);
 
   mListener = new nsImageListener(this);
 
@@ -557,12 +557,12 @@ nsImageFrame::OnSizeAvailable(imgIRequest* aRequest, imgIContainer* aImage)
     // This is valid and for the current request, so update our stored image
     // container, orienting according to our style.
     mImage = nsLayoutUtils::OrientImage(aImage, StyleVisibility()->mImageOrientation);
-    
+
     intrinsicSizeChanged = UpdateIntrinsicSize(mImage);
     intrinsicSizeChanged = UpdateIntrinsicRatio(mImage) || intrinsicSizeChanged;
   } else {
     // We no longer have a valid image, so release our stored image container.
-    mImage = nullptr;
+    mImage = mPrevImage = nullptr;
 
     // Have to size to 0,0 so that GetDesiredSize recalculates the size.
     mIntrinsicSize.width.SetCoordValue(0);
@@ -586,6 +586,8 @@ nsImageFrame::OnSizeAvailable(imgIRequest* aRequest, imgIContainer* aImage)
       // so we're ready to request a decode.
       MaybeDecodeForPredictedSize();
     }
+
+    mPrevImage = nullptr;
   }
 
   return NS_OK;
@@ -675,7 +677,7 @@ nsImageFrame::NotifyNewCurrentRequest(imgIRequest *aRequest,
     intrinsicSizeChanged = UpdateIntrinsicRatio(mImage) || intrinsicSizeChanged;
   } else {
     // We no longer have a valid image, so release our stored image container.
-    mImage = nullptr;
+    mImage = mPrevImage = nullptr;
 
     // Have to size to 0,0 so that GetDesiredSize recalculates the size
     mIntrinsicSize.width.SetCoordValue(0);
@@ -696,6 +698,8 @@ nsImageFrame::NotifyNewCurrentRequest(imgIRequest *aRequest,
         // so we're ready to request a decode.
         MaybeDecodeForPredictedSize();
       }
+
+      mPrevImage = nullptr;
     }
     // Update border+content to account for image change
     InvalidateFrame();
@@ -714,7 +718,7 @@ nsImageFrame::MaybeDecodeForPredictedSize()
     return;  // We won't draw anything, so no point in decoding.
   }
 
-  if (GetVisibility() != Visibility::APPROXIMATELY_VISIBLE) {
+  if (!IsVisibleOrMayBecomeVisibleSoon()) {
     return;  // We're not visible, so don't decode.
   }
 
@@ -1486,7 +1490,8 @@ static void PaintDebugImageMap(nsIFrame* aFrame, DrawTarget* aDrawTarget,
 
 void
 nsDisplayImage::Paint(nsDisplayListBuilder* aBuilder,
-                      nsRenderingContext* aCtx) {
+                      nsRenderingContext* aCtx)
+{
   uint32_t flags = imgIContainer::FLAG_NONE;
   if (aBuilder->ShouldSyncDecodeImages()) {
     flags |= imgIContainer::FLAG_SYNC_DECODE;
@@ -1498,6 +1503,17 @@ nsDisplayImage::Paint(nsDisplayListBuilder* aBuilder,
   DrawResult result = static_cast<nsImageFrame*>(mFrame)->
     PaintImage(*aCtx, ToReferenceFrame(), mVisibleRect, mImage, flags);
 
+  if (result == DrawResult::NOT_READY ||
+      result == DrawResult::INCOMPLETE ||
+      result == DrawResult::TEMPORARY_ERROR) {
+    // If the current image failed to paint because it's still loading or
+    // decoding, try painting the previous image.
+    if (mPrevImage) {
+      result = static_cast<nsImageFrame*>(mFrame)->
+        PaintImage(*aCtx, ToReferenceFrame(), mVisibleRect, mPrevImage, flags);
+    }
+  }
+
   nsDisplayItemGenericImageGeometry::UpdateDrawResult(this, result);
 }
 
@@ -1692,6 +1708,12 @@ nsImageFrame::PaintImage(nsRenderingContext& aRenderingContext, nsPoint aPt,
     map->Draw(this, *drawTarget, black, strokeOptions);
   }
 
+  if (result == DrawResult::SUCCESS) {
+    mPrevImage = aImage;
+  } else if (result == DrawResult::BAD_IMAGE) {
+    mPrevImage = nullptr;
+  }
+
   return result;
 }
 
@@ -1746,7 +1768,7 @@ nsImageFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
       }
     } else {
       aLists.Content()->AppendNewToTop(new (aBuilder)
-        nsDisplayImage(aBuilder, this, mImage));
+        nsDisplayImage(aBuilder, this, mImage, mPrevImage));
 
       // If we were previously displaying an icon, we're not anymore
       if (mDisplayingIcon) {
@@ -1998,7 +2020,7 @@ nsImageFrame::HandleEvent(nsPresContext* aPresContext,
     }
   }
 
-  return ImageFrameSuper::HandleEvent(aPresContext, aEvent, aEventStatus);
+  return nsAtomicContainerFrame::HandleEvent(aPresContext, aEvent, aEventStatus);
 }
 
 nsresult
@@ -2035,8 +2057,8 @@ nsImageFrame::AttributeChanged(int32_t aNameSpaceID,
                                nsIAtom* aAttribute,
                                int32_t aModType)
 {
-  nsresult rv = ImageFrameSuper::AttributeChanged(aNameSpaceID,
+  nsresult rv = nsAtomicContainerFrame::AttributeChanged(aNameSpaceID,
-                                                  aAttribute, aModType);
+                                                         aAttribute, aModType);
   if (NS_FAILED(rv)) {
     return rv;
   }
@@ -2057,16 +2079,18 @@ nsImageFrame::OnVisibilityChange(Visibility aNewVisibility,
   nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(mContent);
   if (!imageLoader) {
     MOZ_ASSERT_UNREACHABLE("Should have an nsIImageLoadingContent");
+    nsAtomicContainerFrame::OnVisibilityChange(aNewVisibility, aNonvisibleAction);
     return;
   }
 
   imageLoader->OnVisibilityChange(aNewVisibility, aNonvisibleAction);
 
-  if (aNewVisibility == Visibility::APPROXIMATELY_VISIBLE) {
+  if (aNewVisibility == Visibility::MAY_BECOME_VISIBLE ||
+      aNewVisibility == Visibility::IN_DISPLAYPORT) {
     MaybeDecodeForPredictedSize();
   }
 
-  ImageFrameSuper::OnVisibilityChange(aNewVisibility, aNonvisibleAction);
+  nsAtomicContainerFrame::OnVisibilityChange(aNewVisibility, aNonvisibleAction);
 }
 
 nsIAtom*

layout/generic/nsImageFrame.h

@@ -58,10 +58,8 @@ private:
   nsImageFrame *mFrame;
 };
 
-typedef nsAtomicContainerFrame ImageFrameSuper;
+class nsImageFrame : public nsAtomicContainerFrame
-
+                   , public nsIReflowCallback {
-class nsImageFrame : public ImageFrameSuper,
-                     public nsIReflowCallback {
 public:
   template <typename T> using Maybe = mozilla::Maybe<T>;
   using Nothing = mozilla::Nothing;
@@ -119,7 +117,7 @@ public:
 
   virtual bool IsFrameOfType(uint32_t aFlags) const override
   {
-    return ImageFrameSuper::IsFrameOfType(aFlags &
+    return nsAtomicContainerFrame::IsFrameOfType(aFlags &
       ~(nsIFrame::eReplaced | nsIFrame::eReplacedSizing));
   }
 
@@ -333,6 +331,7 @@ private:
   nsCOMPtr<imgINotificationObserver> mListener;
 
   nsCOMPtr<imgIContainer> mImage;
+  nsCOMPtr<imgIContainer> mPrevImage;
   nsSize mComputedSize;
   mozilla::IntrinsicSize mIntrinsicSize;
   nsSize mIntrinsicRatio;
@@ -413,8 +412,11 @@ public:
   typedef mozilla::layers::LayerManager LayerManager;
 
   nsDisplayImage(nsDisplayListBuilder* aBuilder, nsImageFrame* aFrame,
-                 imgIContainer* aImage)
+                 imgIContainer* aImage, imgIContainer* aPrevImage)
-    : nsDisplayImageContainer(aBuilder, aFrame), mImage(aImage) {
+    : nsDisplayImageContainer(aBuilder, aFrame)
+    , mImage(aImage)
+    , mPrevImage(aPrevImage)
+  {
     MOZ_COUNT_CTOR(nsDisplayImage);
   }
   virtual ~nsDisplayImage() {
@@ -463,6 +465,7 @@ public:
   NS_DISPLAY_DECL_NAME("Image", TYPE_IMAGE)
 private:
   nsCOMPtr<imgIContainer> mImage;
+  nsCOMPtr<imgIContainer> mPrevImage;
 };
 
 #endif /* nsImageFrame_h___ */

layout/generic/nsInlineFrame.cpp

@@ -71,7 +71,7 @@ nsInlineFrame::InvalidateFrame(uint32_t aDisplayItemKey)
     svgTextFrame->InvalidateFrame();
     return;
   }
-  nsInlineFrameBase::InvalidateFrame(aDisplayItemKey);
+  nsContainerFrame::InvalidateFrame(aDisplayItemKey);
 }
 
 void
@@ -84,7 +84,7 @@ nsInlineFrame::InvalidateFrameWithRect(const nsRect& aRect, uint32_t aDisplayIte
     svgTextFrame->InvalidateFrame();
     return;
   }
-  nsInlineFrameBase::InvalidateFrameWithRect(aRect, aDisplayItemKey);
+  nsContainerFrame::InvalidateFrameWithRect(aRect, aDisplayItemKey);
 }
 
 static inline bool
@@ -482,7 +482,7 @@ nsInlineFrame::AttributeChanged(int32_t aNameSpaceID,
                                 int32_t aModType)
 {
   nsresult rv =
-    nsInlineFrameBase::AttributeChanged(aNameSpaceID, aAttribute, aModType);
+    nsContainerFrame::AttributeChanged(aNameSpaceID, aAttribute, aModType);
 
   if (NS_FAILED(rv)) {
     return rv;

layout/generic/nsInlineFrame.h

@@ -13,15 +13,13 @@
 
 class nsLineLayout;
 
-typedef nsContainerFrame nsInlineFrameBase;
-
 /**
  * Inline frame class.
  *
  * This class manages a list of child frames that are inline frames. Working with
  * nsLineLayout, the class will reflow and place inline frames on a line.
  */
-class nsInlineFrame : public nsInlineFrameBase
+class nsInlineFrame : public nsContainerFrame
 {
 public:
   NS_DECL_QUERYFRAME_TARGET(nsInlineFrame)

layout/generic/nsPluginFrame.cpp

@@ -150,7 +150,7 @@ protected:
 };
 
 nsPluginFrame::nsPluginFrame(nsStyleContext* aContext)
-  : nsPluginFrameSuper(aContext)
+  : nsFrame(aContext)
   , mInstanceOwner(nullptr)
   , mReflowCallbackPosted(false)
   , mIsHiddenDueToScroll(false)
@@ -168,7 +168,7 @@ nsPluginFrame::~nsPluginFrame()
 NS_QUERYFRAME_HEAD(nsPluginFrame)
   NS_QUERYFRAME_ENTRY(nsPluginFrame)
   NS_QUERYFRAME_ENTRY(nsIObjectFrame)
-NS_QUERYFRAME_TAIL_INHERITING(nsPluginFrameSuper)
+NS_QUERYFRAME_TAIL_INHERITING(nsFrame)
 
 #ifdef ACCESSIBILITY
 a11y::AccType
@@ -194,7 +194,7 @@ nsPluginFrame::Init(nsIContent*       aContent,
   MOZ_LOG(sPluginFrameLog, LogLevel::Debug,
          ("Initializing nsPluginFrame %p for content %p\n", this, aContent));
 
-  nsPluginFrameSuper::Init(aContent, aParent, aPrevInFlow);
+  nsFrame::Init(aContent, aParent, aPrevInFlow);
 }
 
 void
@@ -223,7 +223,7 @@ nsPluginFrame::DestroyFrom(nsIFrame* aDestructRoot)
     mBackgroundSink->Destroy();
   }
 
-  nsPluginFrameSuper::DestroyFrom(aDestructRoot);
+  nsFrame::DestroyFrom(aDestructRoot);
 }
 
 /* virtual */ void
@@ -239,7 +239,7 @@ nsPluginFrame::DidSetStyleContext(nsStyleContext* aOldStyleContext)
     }
   }
 
-  nsPluginFrameSuper::DidSetStyleContext(aOldStyleContext);
+  nsFrame::DidSetStyleContext(aOldStyleContext);
 }
 
 nsIAtom*
@@ -737,7 +737,7 @@ nsPluginFrame::IsFocusable(int32_t *aTabIndex, bool aWithMouse)
 {
   if (aTabIndex)
     *aTabIndex = -1;
-  return nsPluginFrameSuper::IsFocusable(aTabIndex, aWithMouse);
+  return nsFrame::IsFocusable(aTabIndex, aWithMouse);
 }
 
 bool
@@ -853,7 +853,7 @@ nsPluginFrame::DidReflow(nsPresContext*            aPresContext,
     objContent->HasNewFrame(this);
   }
 
-  nsPluginFrameSuper::DidReflow(aPresContext, aReflowState, aStatus);
+  nsFrame::DidReflow(aPresContext, aReflowState, aStatus);
 
   // The view is created hidden; once we have reflowed it and it has been
   // positioned then we show it.
@@ -1674,7 +1674,7 @@ nsPluginFrame::HandleEvent(nsPresContext* aPresContext,
   }
 
 #ifdef XP_WIN
-  rv = nsPluginFrameSuper::HandleEvent(aPresContext, anEvent, anEventStatus);
+  rv = nsFrame::HandleEvent(aPresContext, anEvent, anEventStatus);
   return rv;
 #endif
 
@@ -1698,10 +1698,10 @@ nsPluginFrame::HandleEvent(nsPresContext* aPresContext,
   }
 #endif
 
-  rv = nsPluginFrameSuper::HandleEvent(aPresContext, anEvent, anEventStatus);
+  rv = nsFrame::HandleEvent(aPresContext, anEvent, anEventStatus);
 
   // We need to be careful from this point because the call to
-  // nsPluginFrameSuper::HandleEvent() might have killed us.
+  // nsFrame::HandleEvent() might have killed us.
 
 #ifdef XP_MACOSX
   if (anEvent->mMessage == eMouseUp) {
@@ -1786,7 +1786,7 @@ nsPluginFrame::GetCursor(const nsPoint& aPoint, nsIFrame::Cursor& aCursor)
     return NS_ERROR_FAILURE;
   }
 
-  return nsPluginFrameSuper::GetCursor(aPoint, aCursor);
+  return nsFrame::GetCursor(aPoint, aCursor);
 }
 
 void

layout/generic/nsPluginFrame.h

@@ -42,13 +42,11 @@ class LayerManager;
 } // namespace layers
 } // namespace mozilla
 
-typedef nsFrame nsPluginFrameSuper;
-
 class PluginFrameDidCompositeObserver;
 
-class nsPluginFrame : public nsPluginFrameSuper,
+class nsPluginFrame : public nsFrame
-                      public nsIObjectFrame,
+                    , public nsIObjectFrame
-                      public nsIReflowCallback
+                    , public nsIReflowCallback
 {
 public:
   typedef mozilla::LayerState LayerState;
@@ -91,7 +89,7 @@ public:
 
   virtual bool IsFrameOfType(uint32_t aFlags) const override
   {
-    return nsPluginFrameSuper::IsFrameOfType(aFlags &
+    return nsFrame::IsFrameOfType(aFlags &
       ~(nsIFrame::eReplaced | nsIFrame::eReplacedSizing));
   }
 

layout/generic/nsRubyBaseFrame.cpp

@@ -22,7 +22,7 @@ using namespace mozilla;
 
 NS_QUERYFRAME_HEAD(nsRubyBaseFrame)
   NS_QUERYFRAME_ENTRY(nsRubyBaseFrame)
-NS_QUERYFRAME_TAIL_INHERITING(nsRubyBaseFrameSuper)
+NS_QUERYFRAME_TAIL_INHERITING(nsRubyContentFrame)
 
 NS_IMPL_FRAMEARENA_HELPERS(nsRubyBaseFrame)
 

layout/generic/nsRubyBaseFrame.h

@@ -11,8 +11,6 @@
 
 #include "nsRubyContentFrame.h"
 
-typedef nsRubyContentFrame nsRubyBaseFrameSuper;
-
 /**
  * Factory function.
  * @return a newly allocated nsRubyBaseFrame (infallible)
@@ -20,7 +18,7 @@ typedef nsRubyContentFrame nsRubyBaseFrameSuper;
 nsContainerFrame* NS_NewRubyBaseFrame(nsIPresShell* aPresShell,
                                       nsStyleContext* aContext);
 
-class nsRubyBaseFrame final : public nsRubyBaseFrameSuper
+class nsRubyBaseFrame final : public nsRubyContentFrame
 {
 public:
   NS_DECL_FRAMEARENA_HELPERS
@@ -38,7 +36,7 @@ protected:
   friend nsContainerFrame* NS_NewRubyBaseFrame(nsIPresShell* aPresShell,
                                                nsStyleContext* aContext);
   explicit nsRubyBaseFrame(nsStyleContext* aContext)
-    : nsRubyBaseFrameSuper(aContext) {}
+    : nsRubyContentFrame(aContext) {}
 };
 
 #endif /* nsRubyBaseFrame_h___ */

layout/generic/nsRubyContentFrame.cpp

@@ -24,7 +24,7 @@ nsRubyContentFrame::IsFrameOfType(uint32_t aFlags) const
   if (aFlags & eBidiInlineContainer) {
     return false;
   }
-  return nsRubyContentFrameSuper::IsFrameOfType(aFlags);
+  return nsInlineFrame::IsFrameOfType(aFlags);
 }
 
 bool

layout/generic/nsRubyContentFrame.h

@@ -11,9 +11,7 @@
 
 #include "nsInlineFrame.h"
 
-typedef nsInlineFrame nsRubyContentFrameSuper;
+class nsRubyContentFrame : public nsInlineFrame
-
-class nsRubyContentFrame : public nsRubyContentFrameSuper
 {
 public:
   NS_DECL_ABSTRACT_FRAME(nsRubyContentFrame)
@@ -30,7 +28,7 @@ public:
 
 protected:
   explicit nsRubyContentFrame(nsStyleContext* aContext)
-    : nsRubyContentFrameSuper(aContext) {}
+    : nsInlineFrame(aContext) {}
 };
 
 #endif /* nsRubyContentFrame_h___ */

layout/generic/nsRubyFrame.cpp

@@ -26,7 +26,7 @@ using namespace mozilla;
 
 NS_QUERYFRAME_HEAD(nsRubyFrame)
   NS_QUERYFRAME_ENTRY(nsRubyFrame)
-NS_QUERYFRAME_TAIL_INHERITING(nsRubyFrameSuper)
+NS_QUERYFRAME_TAIL_INHERITING(nsInlineFrame)
 
 NS_IMPL_FRAMEARENA_HELPERS(nsRubyFrame)
 
@@ -54,7 +54,7 @@ nsRubyFrame::IsFrameOfType(uint32_t aFlags) const
   if (aFlags & eBidiInlineContainer) {
     return false;
   }
-  return nsRubyFrameSuper::IsFrameOfType(aFlags);
+  return nsInlineFrame::IsFrameOfType(aFlags);
 }
 
 #ifdef DEBUG_FRAME_DUMP

layout/generic/nsRubyFrame.h

@@ -13,8 +13,6 @@
 
 class nsRubyBaseContainerFrame;
 
-typedef nsInlineFrame nsRubyFrameSuper;
-
 /**
  * Factory function.
  * @return a newly allocated nsRubyFrame (infallible)
@@ -22,7 +20,7 @@ typedef nsInlineFrame nsRubyFrameSuper;
 nsContainerFrame* NS_NewRubyFrame(nsIPresShell* aPresShell,
                                   nsStyleContext* aContext);
 
-class nsRubyFrame final : public nsRubyFrameSuper
+class nsRubyFrame final : public nsInlineFrame
 {
 public:
   NS_DECL_FRAMEARENA_HELPERS
@@ -55,7 +53,7 @@ protected:
   friend nsContainerFrame* NS_NewRubyFrame(nsIPresShell* aPresShell,
                                            nsStyleContext* aContext);
   explicit nsRubyFrame(nsStyleContext* aContext)
-    : nsRubyFrameSuper(aContext) {}
+    : nsInlineFrame(aContext) {}
 
   void ReflowSegment(nsPresContext* aPresContext,
                      const nsHTMLReflowState& aReflowState,

layout/generic/nsRubyTextContainerFrame.cpp

@@ -60,14 +60,14 @@ nsRubyTextContainerFrame::IsFrameOfType(uint32_t aFlags) const
   if (aFlags & eSupportsCSSTransforms) {
     return false;
   }
-  return nsRubyTextContainerFrameSuper::IsFrameOfType(aFlags);
+  return nsContainerFrame::IsFrameOfType(aFlags);
 }
 
 /* virtual */ void
 nsRubyTextContainerFrame::SetInitialChildList(ChildListID aListID,
                                               nsFrameList& aChildList)
 {
-  nsRubyTextContainerFrameSuper::SetInitialChildList(aListID, aChildList);
+  nsContainerFrame::SetInitialChildList(aListID, aChildList);
   if (aListID == kPrincipalList) {
     UpdateSpanFlag();
   }
@@ -77,7 +77,7 @@ nsRubyTextContainerFrame::SetInitialChildList(ChildListID aListID,
 nsRubyTextContainerFrame::AppendFrames(ChildListID aListID,
                                        nsFrameList& aFrameList)
 {
-  nsRubyTextContainerFrameSuper::AppendFrames(aListID, aFrameList);
+  nsContainerFrame::AppendFrames(aListID, aFrameList);
   UpdateSpanFlag();
 }
 
@@ -86,7 +86,7 @@ nsRubyTextContainerFrame::InsertFrames(ChildListID aListID,
                                        nsIFrame* aPrevFrame,
                                        nsFrameList& aFrameList)
 {
-  nsRubyTextContainerFrameSuper::InsertFrames(aListID, aPrevFrame, aFrameList);
+  nsContainerFrame::InsertFrames(aListID, aPrevFrame, aFrameList);
   UpdateSpanFlag();
 }
 
@@ -94,7 +94,7 @@ nsRubyTextContainerFrame::InsertFrames(ChildListID aListID,
 nsRubyTextContainerFrame::RemoveFrame(ChildListID aListID,
                                       nsIFrame* aOldFrame)
 {
-  nsRubyTextContainerFrameSuper::RemoveFrame(aListID, aOldFrame);
+  nsContainerFrame::RemoveFrame(aListID, aOldFrame);
   UpdateSpanFlag();
 }
 

layout/generic/nsRubyTextContainerFrame.h

@@ -11,8 +11,6 @@
 
 #include "nsBlockFrame.h"
 
-typedef nsContainerFrame nsRubyTextContainerFrameSuper;
-
 /**
  * Factory function.
  * @return a newly allocated nsRubyTextContainerFrame (infallible)
@@ -20,7 +18,7 @@ typedef nsContainerFrame nsRubyTextContainerFrameSuper;
 nsContainerFrame* NS_NewRubyTextContainerFrame(nsIPresShell* aPresShell,
                                                nsStyleContext* aContext);
 
-class nsRubyTextContainerFrame final : public nsRubyTextContainerFrameSuper
+class nsRubyTextContainerFrame final : public nsContainerFrame
 {
 public:
   NS_DECL_FRAMEARENA_HELPERS
@@ -59,7 +57,7 @@ protected:
     NS_NewRubyTextContainerFrame(nsIPresShell* aPresShell,
                                  nsStyleContext* aContext);
   explicit nsRubyTextContainerFrame(nsStyleContext* aContext)
-    : nsRubyTextContainerFrameSuper(aContext)
+    : nsContainerFrame(aContext)
     , mISize(0) {}
 
   void UpdateSpanFlag();

layout/generic/nsRubyTextFrame.cpp

@@ -22,7 +22,7 @@ using namespace mozilla;
 
 NS_QUERYFRAME_HEAD(nsRubyTextFrame)
   NS_QUERYFRAME_ENTRY(nsRubyTextFrame)
-NS_QUERYFRAME_TAIL_INHERITING(nsRubyTextFrameSuper)
+NS_QUERYFRAME_TAIL_INHERITING(nsRubyContentFrame)
 
 NS_IMPL_FRAMEARENA_HELPERS(nsRubyTextFrame)
 
@@ -70,7 +70,7 @@ nsRubyTextFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
     return;
   }
 
-  nsRubyTextFrameSuper::BuildDisplayList(aBuilder, aDirtyRect, aLists);
+  nsRubyContentFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
 }
 
 /* virtual */ void
@@ -85,8 +85,7 @@ nsRubyTextFrame::Reflow(nsPresContext* aPresContext,
   // the content is no longer the same, until next reflow triggered by
   // some other change. In general, we always reflow all the frames we
   // created. There might be other problems if we don't do that.
-  nsRubyTextFrameSuper::Reflow(aPresContext, aDesiredSize,
+  nsRubyContentFrame::Reflow(aPresContext, aDesiredSize, aReflowState, aStatus);
-                               aReflowState, aStatus);
 
   if (IsAutoHidden()) {
     // Reset the ISize. The BSize is not changed so that it won't

layout/generic/nsRubyTextFrame.h

@@ -11,8 +11,6 @@
 
 #include "nsRubyContentFrame.h"
 
-typedef nsRubyContentFrame nsRubyTextFrameSuper;
-
 /**
  * Factory function.
  * @return a newly allocated nsRubyTextFrame (infallible)
@@ -20,7 +18,7 @@ typedef nsRubyContentFrame nsRubyTextFrameSuper;
 nsContainerFrame* NS_NewRubyTextFrame(nsIPresShell* aPresShell,
                                       nsStyleContext* aContext);
 
-class nsRubyTextFrame final : public nsRubyTextFrameSuper
+class nsRubyTextFrame final : public nsRubyContentFrame
 {
 public:
   NS_DECL_FRAMEARENA_HELPERS
@@ -53,7 +51,7 @@ protected:
   friend nsContainerFrame* NS_NewRubyTextFrame(nsIPresShell* aPresShell,
                                                nsStyleContext* aContext);
   explicit nsRubyTextFrame(nsStyleContext* aContext)
-    : nsRubyTextFrameSuper(aContext) {}
+    : nsRubyContentFrame(aContext) {}
 };
 
 #endif /* nsRubyTextFrame_h___ */

layout/generic/nsSubDocumentFrame.cpp

@@ -57,7 +57,7 @@ GetDocumentFromView(nsView* aView)
 }
 
 nsSubDocumentFrame::nsSubDocumentFrame(nsStyleContext* aContext)
-  : nsSubDocumentFrameSuper(aContext)
+  : nsAtomicContainerFrame(aContext)
   , mIsInline(false)
   , mPostedReflowCallback(false)
   , mDidCreateDoc(false)
@@ -75,7 +75,7 @@ nsSubDocumentFrame::AccessibleType()
 
 NS_QUERYFRAME_HEAD(nsSubDocumentFrame)
   NS_QUERYFRAME_ENTRY(nsSubDocumentFrame)
-NS_QUERYFRAME_TAIL_INHERITING(nsSubDocumentFrameSuper)
+NS_QUERYFRAME_TAIL_INHERITING(nsAtomicContainerFrame)
 
 class AsyncFrameInit : public nsRunnable
 {
@@ -108,7 +108,7 @@ nsSubDocumentFrame::Init(nsIContent*       aContent,
   nsCOMPtr<nsIDOMHTMLFrameElement> frameElem = do_QueryInterface(aContent);
   mIsInline = frameElem ? false : true;
 
-  nsSubDocumentFrameSuper::Init(aContent, aParent, aPrevInFlow);
+  nsAtomicContainerFrame::Init(aContent, aParent, aPrevInFlow);
 
   // We are going to create an inner view.  If we need a view for the
   // OuterFrame but we wait for the normal view creation path in
@@ -689,7 +689,7 @@ nsSubDocumentFrame::GetIntrinsicSize()
   if (subDocRoot) {
     return subDocRoot->GetIntrinsicSize();
   }
-  return nsSubDocumentFrameSuper::GetIntrinsicSize();
+  return nsAtomicContainerFrame::GetIntrinsicSize();
 }
 
 /* virtual */ nsSize
@@ -699,7 +699,7 @@ nsSubDocumentFrame::GetIntrinsicRatio()
   if (subDocRoot) {
     return subDocRoot->GetIntrinsicRatio();
   }
-  return nsSubDocumentFrameSuper::GetIntrinsicRatio();
+  return nsAtomicContainerFrame::GetIntrinsicRatio();
 }
 
 /* virtual */
@@ -747,10 +747,10 @@ nsSubDocumentFrame::ComputeSize(nsRenderingContext *aRenderingContext,
                             aBorder,
                             aPadding);
   }
-  return nsSubDocumentFrameSuper::ComputeSize(aRenderingContext, aWM,
+  return nsAtomicContainerFrame::ComputeSize(aRenderingContext, aWM,
-                                              aCBSize, aAvailableISize,
+                                             aCBSize, aAvailableISize,
-                                              aMargin, aBorder, aPadding,
+                                             aMargin, aBorder, aPadding,
-                                              aFlags);
+                                             aFlags);
 }
 
 void
@@ -955,18 +955,16 @@ public:
     if (!mPresShell->IsDestroying() && mFrameElement->IsInComposedDoc()) {
       mPresShell->FlushPendingNotifications(Flush_Frames);
     }
-    
+
-    // Either the frame has been constructed by now, or it never will be.
+    // Either the frame has been constructed by now, or it never will be,
-    // Either way, we want to clear the stashed views.
+    // either way we want to clear the stashed views.
     mFrameLoader->SetDetachedSubdocFrame(nullptr, nullptr);
 
-    
     nsSubDocumentFrame* frame = do_QueryFrame(mFrameElement->GetPrimaryFrame());
     if ((!frame && mHideViewerIfFrameless) ||
         mPresShell->IsDestroying()) {
       // Either the frame element has no nsIFrame or the presshell is being
-      // destroyed. Hide the nsFrameLoader, which destroys the presentation,
+      // destroyed. Hide the nsFrameLoader, which destroys the presentation.
-      // and clear our references to the stashed presentation.
       mFrameLoader->Hide();
     }
     return NS_OK;
@@ -1015,7 +1013,7 @@ nsSubDocumentFrame::DestroyFrom(nsIFrame* aDestructRoot)
     }
   }
 
-  nsSubDocumentFrameSuper::DestroyFrom(aDestructRoot);
+  nsAtomicContainerFrame::DestroyFrom(aDestructRoot);
 }
 
 CSSIntSize

layout/generic/nsSubDocumentFrame.h

@@ -12,12 +12,10 @@
 #include "nsFrameLoader.h"
 #include "Units.h"
 
-typedef nsAtomicContainerFrame nsSubDocumentFrameSuper;
-
 /******************************************************************************
  * nsSubDocumentFrame
  *****************************************************************************/
-class nsSubDocumentFrame : public nsSubDocumentFrameSuper,
+class nsSubDocumentFrame : public nsAtomicContainerFrame,
                            public nsIReflowCallback
 {
 public:
@@ -37,7 +35,7 @@ public:
 
   virtual bool IsFrameOfType(uint32_t aFlags) const override
   {
-    return nsSubDocumentFrameSuper::IsFrameOfType(aFlags &
+    return nsAtomicContainerFrame::IsFrameOfType(aFlags &
       ~(nsIFrame::eReplaced |
         nsIFrame::eReplacedSizing |
         nsIFrame::eReplacedContainsBlock));

layout/generic/nsVideoFrame.cpp

@@ -75,7 +75,7 @@ SwapScaleWidthHeightForRotation(IntSize& aSize, VideoInfo::Rotation aDegrees)
 }
 
 nsVideoFrame::nsVideoFrame(nsStyleContext* aContext)
-  : nsVideoFrameBase(aContext)
+  : nsContainerFrame(aContext)
 {
   EnableVisibilityTracking();
 }
@@ -87,7 +87,7 @@ nsVideoFrame::~nsVideoFrame()
 NS_QUERYFRAME_HEAD(nsVideoFrame)
   NS_QUERYFRAME_ENTRY(nsVideoFrame)
   NS_QUERYFRAME_ENTRY(nsIAnonymousContentCreator)
-NS_QUERYFRAME_TAIL_INHERITING(nsVideoFrameBase)
+NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
 
 nsresult
 nsVideoFrame::CreateAnonymousContent(nsTArray<ContentInfo>& aElements)
@@ -178,7 +178,7 @@ nsVideoFrame::DestroyFrom(nsIFrame* aDestructRoot)
   nsContentUtils::DestroyAnonymousContent(&mCaptionDiv);
   nsContentUtils::DestroyAnonymousContent(&mVideoControls);
   nsContentUtils::DestroyAnonymousContent(&mPosterImage);
-  nsVideoFrameBase::DestroyFrom(aDestructRoot);
+  nsContainerFrame::DestroyFrom(aDestructRoot);
 }
 
 bool
@@ -655,7 +655,7 @@ nsVideoFrame::AttributeChanged(int32_t aNameSpaceID,
   if (aAttribute == nsGkAtoms::poster && HasVideoElement()) {
     UpdatePosterSource(true);
   }
-  return nsVideoFrameBase::AttributeChanged(aNameSpaceID,
+  return nsContainerFrame::AttributeChanged(aNameSpaceID,
                                             aAttribute,
                                             aModType);
 }
@@ -666,12 +666,13 @@ nsVideoFrame::OnVisibilityChange(Visibility aNewVisibility,
 {
   nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(mPosterImage);
   if (!imageLoader) {
+    nsContainerFrame::OnVisibilityChange(aNewVisibility, aNonvisibleAction);
     return;
   }
 
   imageLoader->OnVisibilityChange(aNewVisibility, aNonvisibleAction);
 
-  nsVideoFrameBase::OnVisibilityChange(aNewVisibility, aNonvisibleAction);
+  nsContainerFrame::OnVisibilityChange(aNewVisibility, aNonvisibleAction);
 }
 
 bool nsVideoFrame::HasVideoElement() {

layout/generic/nsVideoFrame.h

@@ -26,9 +26,8 @@ class nsAString;
 class nsPresContext;
 class nsDisplayItem;
 
-typedef nsContainerFrame nsVideoFrameBase;
+class nsVideoFrame : public nsContainerFrame
-
+                   , public nsIAnonymousContentCreator
-class nsVideoFrame : public nsVideoFrameBase, public nsIAnonymousContentCreator
 {
 public:
   template <typename T> using Maybe = mozilla::Maybe<T>;

layout/generic/nsViewportFrame.cpp

@@ -36,7 +36,7 @@ ViewportFrame::Init(nsIContent*       aContent,
                     nsContainerFrame* aParent,
                     nsIFrame*         aPrevInFlow)
 {
-  Super::Init(aContent, aParent, aPrevInFlow);
+  nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
 
   nsIFrame* parent = nsLayoutUtils::GetCrossDocParentFrame(this);
   if (parent) {

layout/generic/nsViewportFrame.h

@@ -27,8 +27,6 @@ public:
   NS_DECL_QUERYFRAME
   NS_DECL_FRAMEARENA_HELPERS
 
-  typedef nsContainerFrame Super;
-
   explicit ViewportFrame(nsStyleContext* aContext)
     : nsContainerFrame(aContext)
   {}

layout/reftests/async-scrolling/perspective-scrolling-4-ref.html

@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html lang="en">
+<meta charset="utf-8">
+<title>Reference: Perspective scrolling with nested clips</title>
+
+<style>
+
+html {
+  padding: 50px 0 3000px;
+}
+
+body {
+  margin: 0;
+}
+
+.scrollbox {
+  width: 600px;
+  height: 500px;
+  perspective: 1px;
+  overflow: auto;
+}
+
+.transformed {
+  will-change: transform;
+  width: 200px;
+  height: 200px;
+  margin: 200px 100px;
+  border: 10px solid black;
+}
+
+.spacer {
+  height: 4000px;
+}
+
+</style>
+
+<div class="scrollbox">
+  <div class="transformed"></div>
+  <div class="spacer"></div>
+</div>
+
+<script>
+document.scrollingElement.scrollTop = 250;
+</script>

layout/reftests/async-scrolling/perspective-scrolling-4.html

@@ -0,0 +1,49 @@
+<!DOCTYPE html>
+<html lang="en"
+     reftest-async-scroll
+     reftest-displayport-x="0" reftest-displayport-y="0"
+     reftest-displayport-w="800" reftest-displayport-h="1000"
+     reftest-async-scroll-x="0" reftest-async-scroll-y="250">
+<meta charset="utf-8">
+<title>Perspective scrolling with nested clips</title>
+
+<style>
+
+html {
+  padding: 50px 0 3000px;
+}
+
+body {
+  margin: 0;
+}
+
+.scrollbox {
+  width: 600px;
+  height: 500px;
+  perspective: 1px;
+  overflow: auto;
+}
+
+.transformed {
+  will-change: transform;
+  width: 200px;
+  height: 200px;
+  margin: 200px 100px;
+  border: 10px solid black;
+}
+
+.spacer {
+  height: 4000px;
+}
+
+</style>
+
+<div class="scrollbox"
+     reftest-displayport-x="0" reftest-displayport-y="0"
+     reftest-displayport-w="600" reftest-displayport-h="2000"
+     reftest-async-scroll-x="0" reftest-async-scroll-y="0">
+
+  <div class="transformed"></div>
+  <div class="spacer"></div>
+
+</div>

layout/reftests/async-scrolling/reftest.list

@@ -30,6 +30,7 @@ skip-if(!asyncPan) == position-fixed-iframe-2.html position-fixed-iframe-2-ref.h
 skip-if(!asyncPan) == position-fixed-in-scroll-container.html position-fixed-in-scroll-container-ref.html
 fuzzy(1,60000) skip-if(!asyncPan) == group-opacity-surface-size-1.html group-opacity-surface-size-1-ref.html
 skip-if(!asyncPan) == offscreen-prerendered-active-opacity.html offscreen-prerendered-active-opacity-ref.html
+fuzzy-if(Android,7,4) skip-if(!asyncPan) == perspective-scrolling-4.html perspective-scrolling-4-ref.html
 
 # for the following tests, we want to disable the low-precision buffer
 # as it will expand the displayport beyond what the test specifies in

layout/reftests/forms/textarea/reftest.list

@@ -1,11 +1,11 @@
-skip-if(B2G||Mulet) fails-if(Android) == resize.html resize-ref.html # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(B2G||Mulet||Android) == resize.html resize-ref.html # Initial mulet triage: parity with B2G/B2G Desktop
 # an offset seems to apply to the native resizer on windows so skip this test for now
-skip-if(B2G||Mulet) fails-if(Android) skip-if(winWidget) fuzzy-if(cocoaWidget,1,33) == resize-background.html resize-background-ref.html # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(B2G||Mulet||Android) skip-if(winWidget) fuzzy-if(cocoaWidget,1,33) == resize-background.html resize-background-ref.html # Initial mulet triage: parity with B2G/B2G Desktop
-skip-if(B2G||Mulet) fails-if(Android) != ltr.html rtl.html # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(B2G||Mulet||Android) != ltr.html rtl.html # Initial mulet triage: parity with B2G/B2G Desktop
-skip-if(B2G||Mulet) fails-if(Android) != ltr-scrollbar.html rtl-scrollbar.html # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(B2G||Mulet||Android) != ltr-scrollbar.html rtl-scrollbar.html # Initial mulet triage: parity with B2G/B2G Desktop
-skip-if(B2G||Mulet) fails-if(Android) != in-ltr-doc-scrollbar.html in-rtl-doc-scrollbar.html # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(B2G||Mulet||Android) != in-ltr-doc-scrollbar.html in-rtl-doc-scrollbar.html # Initial mulet triage: parity with B2G/B2G Desktop
-skip-if(B2G||Mulet) fails-if(Android) != ltr.html no-resize.html # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(B2G||Mulet||Android) != ltr.html no-resize.html # Initial mulet triage: parity with B2G/B2G Desktop
-skip-if(B2G||Mulet) fails-if(Android) fails-if(gtkWidget) != rtl.html no-resize.html # bug 834724 # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(B2G||Mulet||Android) fails-if(xulRuntime.widgetToolkit=="gtk2") != rtl.html no-resize.html # bug 834724 # Initial mulet triage: parity with B2G/B2G Desktop
 == rtl.html rtl-dynamic-attr.html
 == rtl.html rtl-dynamic-style.html
 == rtl.html in-dynamic-rtl-doc.html

layout/reftests/forms/textbox/reftest.list

@@ -1,10 +1,11 @@
 # access-key tests are no use on OS X because access keys are not indicated visually
-skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)) != accesskey-1.xul accesskey-1-notref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
+# no real XUL theme on Android so we just skip
-skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)) == accesskey-2.xul accesskey-2-ref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)||Android) != accesskey-1.xul accesskey-1-notref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)||Android) == accesskey-2.xul accesskey-2-ref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
 # accesskey-3 fails because of defects in XUL bidi support
-fails-if(!cocoaWidget) skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)) == accesskey-3.xul accesskey-3-ref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
+fails-if(!cocoaWidget) skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)||Android) == accesskey-3.xul accesskey-3-ref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
-skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)) != accesskey-3.xul accesskey-3-notref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)||Android) != accesskey-3.xul accesskey-3-notref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
-skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)) == accesskey-4.xul accesskey-4-ref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)||Android) == accesskey-4.xul accesskey-4-ref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
-skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)) != accesskey-4.xul accesskey-4-notref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(cocoaWidget||((B2G&&browserIsRemote)||Mulet)||Android) != accesskey-4.xul accesskey-4-notref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
-skip-if((B2G&&browserIsRemote)||Mulet) == align-baseline-1.xul align-baseline-1-ref.xul # test for bug 494901 # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if((B2G&&browserIsRemote)||Mulet||Android) == align-baseline-1.xul align-baseline-1-ref.xul # test for bug 494901 # Initial mulet triage: parity with B2G/B2G Desktop
-fails-if(Android) skip-if(B2G||Mulet) == setsize.xul setsize-ref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(B2G||Mulet||Android) == setsize.xul setsize-ref.xul # bug 974780 # Initial mulet triage: parity with B2G/B2G Desktop

layout/reftests/reftest.list

@@ -246,7 +246,7 @@ include marquee/reftest.list
 
 # native-theme/
 # skipping for B2G since something around radio-nonnative.html makes the whole suite hang
-skip-if(B2G||Mulet) include native-theme/reftest.list # Initial mulet triage: parity with B2G/B2G Desktop
+skip-if(B2G||Android||Mulet) include native-theme/reftest.list # Initial mulet triage: parity with B2G/B2G Desktop
 
 # netwerk/
 include ../../netwerk/test/reftest/reftest.list
@@ -373,17 +373,20 @@ include ../../widget/reftests/reftest.list
 # xml-stylesheet/
 include ../../content/test/reftest/xml-stylesheet/reftest.list
 
-# xul-document-load/
+# xul-document-load/ (no XUL theme on Android)
-include xul-document-load/reftest.list
+skip-if(Android) include xul-document-load/reftest.list
 
-# xul/
+# xul/ (no XUL theme on Android)
-include xul/reftest.list
+skip-if(Android) include xul/reftest.list
 
-# xul
+# xul (no XUL theme on Android)
-include ../xul/reftest/reftest.list
+skip-if(Android) include ../xul/reftest/reftest.list
 
-# xul grid
+# xul grid (no XUL theme on Android)
-include ../xul/grid/reftests/reftest.list
+skip-if(Android) include ../xul/grid/reftests/reftest.list
+
+# -webkit-box & associated properties (mapped to modern flexbox)
+include webkit-box/reftest.list
 
 # -webkit-gradient expressions
 include webkit-gradient/reftest.list

layout/reftests/webkit-box/reftest.list

@@ -19,6 +19,22 @@ fails == webkit-box-anon-flex-items-3.html webkit-box-anon-flex-items-3-ref.html
 == webkit-box-align-horiz-1b.html webkit-box-align-horiz-1-ref.html
 == webkit-box-align-vert-1.html webkit-box-align-vert-1-ref.html
 
+# Tests for "-webkit-box-direction":
+== webkit-box-direction-1.html webkit-box-direction-1-ref.html
+
+# Tests for "-webkit-box-flex" (flexibility of items)
+== webkit-box-flex-1.html webkit-box-flex-1-ref.html
+
+# Tests for "-webkit-box-ordinal-group"
+== webkit-box-ordinal-group-1.html webkit-box-ordinal-group-1-ref.html
+# XXXdholbert The following test fails because we accept "0" as a valid value
+# for -webkit-box-ordinal-group (unlike Chrome/Blink), because that's simply
+# how its aliased property (-moz-box-ordinal-group) behaves. This shouldn't
+# matter in practice; it could only cause trouble if sites accidentally depend
+# on the "0" value being rejected.
+fails == webkit-box-ordinal-group-2.html webkit-box-ordinal-group-2-ref.html
+== webkit-box-ordinal-group-3.html webkit-box-ordinal-group-3-ref.html
+
 # Tests for "-webkit-box-pack" (main-axis alignment):
 == webkit-box-pack-horiz-1a.html webkit-box-pack-horiz-1-ref.html
 == webkit-box-pack-horiz-1b.html webkit-box-pack-horiz-1-ref.html

layout/reftests/webkit-box/webkit-box-align-horiz-1-ref.html

@@ -0,0 +1,172 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Reference
+  </title>
+  <style>
+    .box {
+      display: flex;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+      /* auto width */
+      height: 1em;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+      font-size: 50%;
+      width: 2em;
+      /* auto height */
+    }
+
+    .bastart    { align-items: flex-start; }
+    .bacenter   { align-items: center;     }
+    .baend      { align-items: flex-end;   }
+    .babaseline { align-items: baseline;   }
+    .bastretch  { align-items: stretch;    }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-align -->
+  <!-- intrinsically sized -->
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- SECOND ROW:  -webkit-box-align: start -->
+  <!-- intrinsically sized -->
+  <div class="box bastart">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bastart" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bastart" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bastart" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- THIRD ROW:  -webkit-box-align: center -->
+  <!-- intrinsically sized -->
+  <div class="box bacenter">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bacenter" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bacenter" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bacenter" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FOURTH ROW:  -webkit-box-align: end -->
+  <!-- intrinsically sized -->
+  <div class="box baend">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box baend" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box baend" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box baend" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FIFTH ROW:  -webkit-box-align: baseline -->
+  <!-- intrinsically sized -->
+  <div class="box babaseline">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box babaseline" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box babaseline" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box babaseline" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+  <!-- SIXTH ROW:  -webkit-box-align: stretch -->
+  <!-- intrinsically sized -->
+  <div class="box bastretch">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bastretch" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bastretch" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bastretch" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-align-horiz-1a.html

@@ -0,0 +1,173 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: horizontally-oriented "display: -webkit-box" container,
+    with all the various -webkit-box-align values.
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+      /* auto width */
+      height: 1em;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+      font-size: 50%;
+      width: 2em;
+      /* auto height */
+    }
+
+    .bastart    { -webkit-box-align: start;    }
+    .bacenter   { -webkit-box-align: center;   }
+    .baend      { -webkit-box-align: end;      }
+    .babaseline { -webkit-box-align: baseline; }
+    .bastretch  { -webkit-box-align: stretch;  }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-align -->
+  <!-- intrinsically sized -->
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- SECOND ROW:  -webkit-box-align: start -->
+  <!-- intrinsically sized -->
+  <div class="box bastart">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bastart" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bastart" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bastart" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- THIRD ROW:  -webkit-box-align: center -->
+  <!-- intrinsically sized -->
+  <div class="box bacenter">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bacenter" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bacenter" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bacenter" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FOURTH ROW:  -webkit-box-align: end -->
+  <!-- intrinsically sized -->
+  <div class="box baend">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box baend" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box baend" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box baend" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FIFTH ROW:  -webkit-box-align: baseline -->
+  <!-- intrinsically sized -->
+  <div class="box babaseline">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box babaseline" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box babaseline" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box babaseline" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+  <!-- SIXTH ROW:  -webkit-box-align: stretch -->
+  <!-- intrinsically sized -->
+  <div class="box bastretch">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bastretch" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bastretch" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bastretch" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-align-horiz-1b.html

@@ -0,0 +1,174 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: horizontally-oriented "display: -webkit-box" container,
+    with all the various -webkit-box-align values.
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      -webkit-box-orient: horizontal;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+      /* auto width */
+      height: 1em;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+      font-size: 50%;
+      width: 2em;
+      /* auto height */
+    }
+
+    .bastart    { -webkit-box-align: start;    }
+    .bacenter   { -webkit-box-align: center;   }
+    .baend      { -webkit-box-align: end;      }
+    .babaseline { -webkit-box-align: baseline; }
+    .bastretch  { -webkit-box-align: stretch;  }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-align -->
+  <!-- intrinsically sized -->
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- SECOND ROW:  -webkit-box-align: start -->
+  <!-- intrinsically sized -->
+  <div class="box bastart">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bastart" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bastart" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bastart" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- THIRD ROW:  -webkit-box-align: center -->
+  <!-- intrinsically sized -->
+  <div class="box bacenter">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bacenter" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bacenter" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bacenter" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FOURTH ROW:  -webkit-box-align: end -->
+  <!-- intrinsically sized -->
+  <div class="box baend">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box baend" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box baend" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box baend" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FIFTH ROW:  -webkit-box-align: baseline -->
+  <!-- intrinsically sized -->
+  <div class="box babaseline">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box babaseline" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box babaseline" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box babaseline" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+  <!-- SIXTH ROW:  -webkit-box-align: stretch -->
+  <!-- intrinsically sized -->
+  <div class="box bastretch">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bastretch" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bastretch" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bastretch" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-align-vert-1-ref.html

@@ -0,0 +1,173 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Reference
+  </title>
+  <style>
+    .box {
+      display: flex;
+      flex-direction: column;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+      /* auto width */
+      height: 1em;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+      font-size: 50%;
+      width: 2em;
+      /* auto height */
+    }
+
+    .bastart    { align-items: flex-start; }
+    .bacenter   { align-items: center;     }
+    .baend      { align-items: flex-end;   }
+    .babaseline { align-items: baseline;   }
+    .bastretch  { align-items: stretch;    }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-align -->
+  <!-- intrinsically sized -->
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- SECOND ROW:  -webkit-box-align: start -->
+  <!-- intrinsically sized -->
+  <div class="box bastart">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bastart" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bastart" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bastart" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- THIRD ROW:  -webkit-box-align: center -->
+  <!-- intrinsically sized -->
+  <div class="box bacenter">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bacenter" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bacenter" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bacenter" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FOURTH ROW:  -webkit-box-align: end -->
+  <!-- intrinsically sized -->
+  <div class="box baend">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box baend" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box baend" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box baend" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FIFTH ROW:  -webkit-box-align: baseline -->
+  <!-- intrinsically sized -->
+  <div class="box babaseline">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box babaseline" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box babaseline" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box babaseline" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+  <!-- SIXTH ROW:  -webkit-box-align: stretch -->
+  <!-- intrinsically sized -->
+  <div class="box bastretch">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bastretch" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bastretch" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bastretch" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-align-vert-1.html

@@ -0,0 +1,174 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: vertically-oriented "display: -webkit-box" container,
+    with all the various -webkit-box-align values.
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      -webkit-box-orient: vertical;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+      /* auto width */
+      height: 1em;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+      font-size: 50%;
+      width: 2em;
+      /* auto height */
+    }
+
+    .bastart    { -webkit-box-align: start;    }
+    .bacenter   { -webkit-box-align: center;   }
+    .baend      { -webkit-box-align: end;      }
+    .babaseline { -webkit-box-align: baseline; }
+    .bastretch  { -webkit-box-align: stretch;  }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-align -->
+  <!-- intrinsically sized -->
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- SECOND ROW:  -webkit-box-align: start -->
+  <!-- intrinsically sized -->
+  <div class="box bastart">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bastart" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bastart" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bastart" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- THIRD ROW:  -webkit-box-align: center -->
+  <!-- intrinsically sized -->
+  <div class="box bacenter">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bacenter" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bacenter" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bacenter" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FOURTH ROW:  -webkit-box-align: end -->
+  <!-- intrinsically sized -->
+  <div class="box baend">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box baend" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box baend" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box baend" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FIFTH ROW:  -webkit-box-align: baseline -->
+  <!-- intrinsically sized -->
+  <div class="box babaseline">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box babaseline" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box babaseline" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box babaseline" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+  <!-- SIXTH ROW:  -webkit-box-align: stretch -->
+  <!-- intrinsically sized -->
+  <div class="box bastretch">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bastretch" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bastretch" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bastretch" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-direction-1-ref.html

@@ -0,0 +1,82 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Reference
+  </title>
+  <style>
+    .box {
+      display: flex;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+    }
+
+    .rtl { direction: rtl; }
+
+    .horizNormal {
+      flex-direction: row;
+    }
+    .horizReverse {
+      flex-direction: row-reverse;
+    }
+    .vertNormal {
+      flex-direction: column;
+    }
+    .vertReverse {
+      flex-direction: column-reverse;
+    }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: '-webkit-box-orient: horizontal', default 'direction' -->
+  <div class="box horizNormal">
+    <div>a</div><div>b</div>
+  </div>
+  <div class="box horizReverse">
+    <div>a</div><div>b</div>
+  </div>
+
+  <br>
+
+  <!-- SECOND ROW: '-webkit-box-orient: horizontal', 'direction: rtl' -->
+  <div class="box horizNormal rtl">
+    <div>a</div><div>b</div>
+  </div>
+  <div class="box horizReverse rtl">
+    <div>a</div><div>b</div>
+  </div>
+
+  <br>
+
+  <!-- THIRD ROW: '-webkit-box-orient: vertical', default 'direction' -->
+  <div class="box vertNormal">
+    <div>a</div><div>b</div>
+  </div>
+  <div class="box vertReverse">
+    <div>a</div><div>b</div>
+  </div>
+
+  <br>
+
+  <!-- FOURTH ROW: '-webkit-box-orient: vertical', 'direction: rtl' -->
+  <div class="box vertNormal rtl">
+    <div>a</div><div>b</div>
+  </div>
+  <div class="box vertReverse rtl">
+    <div>a</div><div>b</div>
+  </div>
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-direction-1.html

@@ -0,0 +1,87 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: "-webkit-box-direction" property
+    in a -webkit-box with default writing-mode
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+    }
+
+    .rtl { direction: rtl; }
+
+    .horizNormal {
+      -webkit-box-orient: horizontal;
+      -webkit-box-direction: normal;
+    }
+    .horizReverse {
+      -webkit-box-orient: horizontal;
+      -webkit-box-direction: reverse;
+    }
+    .vertNormal {
+      -webkit-box-orient: vertical;
+      -webkit-box-direction: normal;
+    }
+    .vertReverse {
+      -webkit-box-orient: vertical;
+      -webkit-box-direction: reverse;
+    }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: '-webkit-box-orient: horizontal', default 'direction' -->
+  <div class="box horizNormal">
+    <div>a</div><div>b</div>
+  </div>
+  <div class="box horizReverse">
+    <div>a</div><div>b</div>
+  </div>
+
+  <br>
+
+  <!-- SECOND ROW: '-webkit-box-orient: horizontal', 'direction: rtl' -->
+  <div class="box horizNormal rtl">
+    <div>a</div><div>b</div>
+  </div>
+  <div class="box horizReverse rtl">
+    <div>a</div><div>b</div>
+  </div>
+
+  <br>
+
+  <!-- THIRD ROW: '-webkit-box-orient: vertical', default 'direction' -->
+  <div class="box vertNormal">
+    <div>a</div><div>b</div>
+  </div>
+  <div class="box vertReverse">
+    <div>a</div><div>b</div>
+  </div>
+
+  <br>
+
+  <!-- FOURTH ROW: '-webkit-box-orient: vertical', 'direction: rtl' -->
+  <div class="box vertNormal rtl">
+    <div>a</div><div>b</div>
+  </div>
+  <div class="box vertReverse rtl">
+    <div>a</div><div>b</div>
+  </div>
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-flex-1-ref.html

@@ -0,0 +1,101 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Reference
+  </title>
+  <style>
+    .box {
+      display: flex;
+      border: 1px solid black;
+      margin: 5px 20px;
+      width: 100px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > * {
+      /* Modern flexbox (used in this reference case) allows everything to
+         shrink by default, but -webkit-box does not, so we have to turn that
+         feature off to make an accurate reference case. */
+      flex-shrink: 0;
+    }
+
+    .box > *:nth-child(1) { background: turquoise; }
+    .box > *:nth-child(2) { background: salmon;    }
+    .box > *:nth-child(3) { background: yellow;    }
+
+    .huge { width: 120px }
+    .bf1 { flex: 1 1 auto }
+    .bf3 { flex: 3 3 auto }
+
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-flex -->
+  <div class="box">
+    <div>a</div>
+  </div>
+
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <div class="box">
+    <div class="huge">a</div>
+  </div>
+
+  <br>
+
+  <!-- SECOND ROW: One item has nonzero -webkit-box-flex -->
+  <div class="box">
+    <div class="bf1">a</div>
+  </div>
+
+  <div class="box">
+    <div>a</div><div class="bf1">b</div>
+  </div>
+
+  <div class="box">
+    <div class="huge bf1">a</div>
+  </div>
+
+  <br>
+
+  <!-- THIRD ROW: Two items have nonzero (equal) -webkit-box-flex -->
+  <div class="box">
+    <div class="bf1">a</div><div class="bf1">b</div>
+  </div>
+
+  <div class="box">
+    <div class="bf1">a</div><div>b</div><div class="bf1">c</div>
+  </div>
+
+  <div class="box">
+    <div class="huge bf1">a</div>
+    <div>b</div>
+    <div class="huge bf1">c</div>
+  </div>
+
+  <br>
+
+  <!-- FOURTH ROW: Non-equal nonzero -webkit-box-flex values -->
+  <div class="box">
+    <div class="bf1">a</div><div class="bf3">b</div>
+  </div>
+
+  <div class="box">
+    <div class="bf3">a</div><div class="bf1">b</div>
+  </div>
+
+  <div class="box">
+    <div class="huge bf1">a</div>
+    <div class="huge bf3">b</div>
+  </div>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-flex-1.html

@@ -0,0 +1,94 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: "-webkit-box-flex" in a "display: -webkit-box" container
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      border: 1px solid black;
+      margin: 5px 20px;
+      width: 100px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) { background: turquoise; }
+    .box > *:nth-child(2) { background: salmon;    }
+    .box > *:nth-child(3) { background: yellow;    }
+
+    .huge { width: 120px }
+    .bf1 { -webkit-box-flex: 1 }
+    .bf3 { -webkit-box-flex: 3 }
+
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-flex -->
+  <div class="box">
+    <div>a</div>
+  </div>
+
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <div class="box">
+    <div class="huge">a</div>
+  </div>
+
+  <br>
+
+  <!-- SECOND ROW: One item has nonzero -webkit-box-flex -->
+  <div class="box">
+    <div class="bf1">a</div>
+  </div>
+
+  <div class="box">
+    <div>a</div><div class="bf1">b</div>
+  </div>
+
+  <div class="box">
+    <div class="huge bf1">a</div>
+  </div>
+
+  <br>
+
+  <!-- THIRD ROW: Two items have nonzero (equal) -webkit-box-flex -->
+  <div class="box">
+    <div class="bf1">a</div><div class="bf1">b</div>
+  </div>
+
+  <div class="box">
+    <div class="bf1">a</div><div>b</div><div class="bf1">c</div>
+  </div>
+
+  <div class="box">
+    <div class="huge bf1">a</div>
+    <div>b</div>
+    <div class="huge bf1">c</div>
+  </div>
+
+  <br>
+
+  <!-- FOURTH ROW: Non-equal nonzero -webkit-box-flex values -->
+  <div class="box">
+    <div class="bf1">a</div><div class="bf3">b</div>
+  </div>
+
+  <div class="box">
+    <div class="bf3">a</div><div class="bf1">b</div>
+  </div>
+
+  <div class="box">
+    <div class="huge bf1">a</div>
+    <div class="huge bf3">b</div>
+  </div>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-ordinal-group-1-ref.html

@@ -0,0 +1,84 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Reference
+  </title>
+  <style>
+    .box {
+      display: flex;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+    }
+    br { clear: both; }
+
+    .box > * {
+      border: 1px dotted purple;
+    }
+  </style>
+</head>
+<body>
+  <!-- First row: initial value mixed with single specified values -->
+  <div class="box">
+    <div>*</div>
+    <div class="bogOne">1a</div>
+    <div>*</div>
+    <div class="bogOne">1b</div>
+    <div>*</div>
+  </div>
+
+  <div class="box">
+    <div>*</div>
+    <div>*</div>
+    <div>*</div>
+    <div class="bogTwo">2a</div>
+    <div class="bogTwo">2b</div>
+  </div>
+
+  <div class="box">
+    <div>*</div>
+    <div>*</div>
+    <div>*</div>
+    <div class="bogNine">9a</div>
+    <div class="bogNine">9b</div>
+  </div>
+
+  <br>
+
+  <!-- Second row: various mixes of specified values -->
+  <div class="box">
+    <div>*</div>
+    <div class="bogOne">1</div>
+    <div class="bogTwo">2</div>
+    <div class="bogNine">9</div>
+  </div>
+
+  <div class="box">
+    <div class="bogOne">1</div>
+    <div>*</div>
+    <div class="bogTwo">2</div>
+    <div class="bogNine">9</div>
+  </div>
+
+  <div class="box">
+    <div class="bogOne">1</div>
+    <div>*</div>
+    <div class="bogTwo">2a</div>
+    <div class="bogTwo">2b</div>
+    <div class="bogNine">9</div>
+  </div>
+
+  <div class="box">
+    <div class="bogOne">1</div>
+    <div class="bogTwo">2a</div>
+    <div class="bogTwo">2b</div>
+    <div class="bogNine">9a</div>
+    <div class="bogNine">9b</div>
+  </div>
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-ordinal-group-1.html

@@ -0,0 +1,88 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: -webkit-box-ordinal-group inside a -webkit-box
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+    }
+    br { clear: both; }
+
+    .box > * {
+      border: 1px dotted purple;
+    }
+
+    .bogOne  { -webkit-box-ordinal-group: 1; }
+    .bogTwo  { -webkit-box-ordinal-group: 2; }
+    .bogNine { -webkit-box-ordinal-group: 9; }
+  </style>
+</head>
+<body>
+  <!-- First row: initial value mixed with single specified values -->
+  <div class="box">
+    <div>*</div>
+    <div class="bogOne">1a</div>
+    <div>*</div>
+    <div class="bogOne">1b</div>
+    <div>*</div>
+  </div>
+
+  <div class="box">
+    <div>*</div>
+    <div class="bogTwo">2a</div>
+    <div>*</div>
+    <div class="bogTwo">2b</div>
+    <div>*</div>
+  </div>
+
+  <div class="box">
+    <div>*</div>
+    <div class="bogNine">9a</div>
+    <div>*</div>
+    <div class="bogNine">9b</div>
+    <div>*</div>
+  </div>
+
+  <br>
+
+  <!-- Second row: various mixes of specified values -->
+  <div class="box">
+    <div>*</div>
+    <div class="bogOne">1</div>
+    <div class="bogTwo">2</div>
+    <div class="bogNine">9</div>
+  </div>
+
+  <div class="box">
+    <div class="bogNine">9</div>
+    <div class="bogTwo">2</div>
+    <div class="bogOne">1</div>
+    <div>*</div>
+  </div>
+
+  <div class="box">
+    <div class="bogTwo">2a</div>
+    <div class="bogNine">9</div>
+    <div class="bogTwo">2b</div>
+    <div class="bogOne">1</div>
+    <div>*</div>
+  </div>
+
+  <div class="box">
+    <div class="bogTwo">2a</div>
+    <div class="bogNine">9a</div>
+    <div class="bogNine">9b</div>
+    <div class="bogTwo">2b</div>
+    <div class="bogOne">1</div>
+  </div>
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-ordinal-group-2-ref.html

@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Reference
+  </title>
+  <style>
+    .box {
+      display: flex;
+      border: 1px solid black;
+      margin: 5px 20px;
+    }
+
+    .box > * {
+      border: 1px dotted purple;
+    }
+  </style>
+</head>
+<body>
+  <div class="box">
+    <div>1</div>
+    <div>0</div>
+  </div>
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-ordinal-group-2.html

@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: -webkit-box-ordinal-group:0 inside a -webkit-box
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      border: 1px solid black;
+      margin: 5px 20px;
+    }
+
+    .box > * {
+      border: 1px dotted purple;
+    }
+
+    .bogZero { -webkit-box-ordinal-group: 0; }
+    .bogOne  { -webkit-box-ordinal-group: 1; }
+  </style>
+</head>
+<body>
+  <!-- -webkit-box-ordinal-group is strictly positive in Blink & WebKit. 0 is
+       rejected as an invalid value. So, the bogZero element below should
+       end up with the initial value (1) and should *not* be sorted out of its
+       DOM position in the final rendering. -->
+  <div class="box">
+    <div class="bogOne">1</div>
+    <div class="bogZero">0</div>
+  </div>
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-ordinal-group-3-ref.html

@@ -0,0 +1,83 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Reference
+  </title>
+  <style>
+    .box {
+      display: flex;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+    }
+    br { clear: both; }
+
+    .box > * {
+      border: 1px dotted purple;
+    }
+  </style>
+</head>
+<body>
+  <div class="box">
+    <div>*</div>
+    <div>10</div>
+    <div>A</div>
+  </div>
+  <div class="box">
+    <div>*</div>
+    <div>10</div>
+    <div>B</div>
+  </div>
+  <div class="box">
+    <div>*</div>
+    <div>10</div>
+    <div>C</div>
+  </div>
+
+  <br>
+
+  <div class="box">
+    <div>*</div>
+    <div>10</div>
+    <div>D</div>
+  </div>
+  <div class="box">
+    <div>*</div>
+    <div>10</div>
+    <div>E</div>
+  </div>
+  <div class="box">
+    <div>*</div>
+    <div>10</div>
+    <div>F</div>
+  </div>
+
+  <br>
+
+  <div class="box">
+    <div>A</div>
+    <div>B</div>
+  </div>
+  <div class="box">
+    <div>A</div>
+    <div>C</div>
+  </div>
+  <div class="box">
+    <div>A</div>
+    <div>D</div>
+  </div>
+  <div class="box">
+    <div>A</div>
+    <div>E</div>
+  </div>
+  <div class="box">
+    <div>A</div>
+    <div>F</div>
+  </div>
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-ordinal-group-3.html

@@ -0,0 +1,103 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: -webkit-box-ordinal-group with huge values inside a -webkit-box
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+    }
+    br { clear: both; }
+
+    .box > * {
+      border: 1px dotted purple;
+    }
+
+    .bogTen   { -webkit-box-ordinal-group: 10; }
+    .bogHugeA { -webkit-box-ordinal-group: 2147483646; /* 2^31 - 2 */ }
+    .bogHugeB {
+      /* NOTE: This is INT32_MAX, so we may not be able to distinguish this
+         from anything larger than it (if we represent it internally in a
+         32-bit signed integer). However, it's still worth testing larger
+         values against e.g. 10 to be sure they don't overflow into
+         negative territory. */
+      -webkit-box-ordinal-group: 2147483647; /* 2^31 - 1 */ }
+
+    .bogHugeC { -webkit-box-ordinal-group: 4294967294; /* 2^32 - 2 */ }
+    .bogHugeD { -webkit-box-ordinal-group: 4294967295; /* 2^32 - 1 */ }
+    .bogHugeE { -webkit-box-ordinal-group: 4294967296; /* 2^32     */ }
+    .bogHugeF { -webkit-box-ordinal-group: 8589934592; /* 2^33     */ }
+  </style>
+</head>
+<body>
+  <!-- Test each huge value to see if it sorts after smaller values.
+       (The divs with huge values should sort to the right.) -->
+  <div class="box">
+    <div class="bogHugeA">A</div>
+    <div class="bogTen">10</div>
+    <div>*</div>
+  </div>
+  <div class="box">
+    <div class="bogHugeB">B</div>
+    <div class="bogTen">10</div>
+    <div>*</div>
+  </div>
+  <div class="box">
+    <div class="bogHugeC">C</div>
+    <div class="bogTen">10</div>
+    <div>*</div>
+  </div>
+
+  <br>
+
+  <div class="box">
+    <div class="bogHugeD">D</div>
+    <div class="bogTen">10</div>
+    <div>*</div>
+  </div>
+  <div class="box">
+    <div class="bogHugeE">E</div>
+    <div class="bogTen">10</div>
+    <div>*</div>
+  </div>
+  <div class="box">
+    <div class="bogHugeE">F</div>
+    <div class="bogTen">10</div>
+    <div>*</div>
+  </div>
+
+  <br>
+
+  <!-- Test that 'bogHugeA' sorts to the left of larger huge values. It's
+       less than INT32_MAX, so it's reasonable to expect that it can be
+       compared correctly against (possibly-clamped) larger values) -->
+  <div class="box">
+    <div class="bogHugeB">B</div>
+    <div class="bogHugeA">A</div>
+  </div>
+  <div class="box">
+    <div class="bogHugeC">C</div>
+    <div class="bogHugeA">A</div>
+  </div>
+  <div class="box">
+    <div class="bogHugeD">D</div>
+    <div class="bogHugeA">A</div>
+  </div>
+  <div class="box">
+    <div class="bogHugeE">E</div>
+    <div class="bogHugeA">A</div>
+  </div>
+  <div class="box">
+    <div class="bogHugeF">F</div>
+    <div class="bogHugeA">A</div>
+  </div>
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-pack-horiz-1-ref.html

@@ -0,0 +1,150 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Reference
+  </title>
+  <style>
+    .box {
+      display: flex;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+      /* auto width */
+      height: 1em;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+      font-size: 50%;
+      width: 2em;
+      /* auto height */
+    }
+
+    .bpstart   { justify-content: flex-start;    }
+    .bpcenter  { justify-content: center;        }
+    .bpend     { justify-content: flex-end;      }
+    .bpjustify { justify-content: space-between; }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-pack -->
+  <!-- intrinsically sized -->
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- SECOND ROW:  -webkit-box-pack: start -->
+  <!-- intrinsically sized -->
+  <div class="box bpstart">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpstart" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpstart" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpstart" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- THIRD ROW:  -webkit-box-pack: center -->
+  <!-- intrinsically sized -->
+  <div class="box bpcenter">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpcenter" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpcenter" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpcenter" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FOURTH ROW:  -webkit-box-pack: end -->
+  <!-- intrinsically sized -->
+  <div class="box bpend">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpend" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpend" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpend" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FIFTH ROW:  -webkit-box-pack: justify -->
+  <!-- intrinsically sized -->
+  <div class="box bpjustify">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpjustify" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpjustify" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpjustify" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-pack-horiz-1a.html

@@ -0,0 +1,151 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: horizontally-oriented "display: -webkit-box" container,
+    with all the various -webkit-box-pack values.
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+      /* auto width */
+      height: 1em;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+      font-size: 50%;
+      width: 2em;
+      /* auto height */
+    }
+
+    .bpstart   { -webkit-box-pack: start;   }
+    .bpcenter  { -webkit-box-pack: center;  }
+    .bpend     { -webkit-box-pack: end;     }
+    .bpjustify { -webkit-box-pack: justify; }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-pack -->
+  <!-- intrinsically sized -->
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- SECOND ROW:  -webkit-box-pack: start -->
+  <!-- intrinsically sized -->
+  <div class="box bpstart">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpstart" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpstart" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpstart" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- THIRD ROW:  -webkit-box-pack: center -->
+  <!-- intrinsically sized -->
+  <div class="box bpcenter">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpcenter" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpcenter" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpcenter" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FOURTH ROW:  -webkit-box-pack: end -->
+  <!-- intrinsically sized -->
+  <div class="box bpend">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpend" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpend" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpend" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FIFTH ROW:  -webkit-box-pack: justify -->
+  <!-- intrinsically sized -->
+  <div class="box bpjustify">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpjustify" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpjustify" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpjustify" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-pack-horiz-1b.html

@@ -0,0 +1,152 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: horizontally-oriented "display: -webkit-box" container,
+    with all the various -webkit-box-pack values.
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      -webkit-box-orient: horizontal;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+      /* auto width */
+      height: 1em;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+      font-size: 50%;
+      width: 2em;
+      /* auto height */
+    }
+
+    .bpstart   { -webkit-box-pack: start;   }
+    .bpcenter  { -webkit-box-pack: center;  }
+    .bpend     { -webkit-box-pack: end;     }
+    .bpjustify { -webkit-box-pack: justify; }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-pack -->
+  <!-- intrinsically sized -->
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- SECOND ROW:  -webkit-box-pack: start -->
+  <!-- intrinsically sized -->
+  <div class="box bpstart">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpstart" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpstart" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpstart" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- THIRD ROW:  -webkit-box-pack: center -->
+  <!-- intrinsically sized -->
+  <div class="box bpcenter">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpcenter" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpcenter" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpcenter" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FOURTH ROW:  -webkit-box-pack: end -->
+  <!-- intrinsically sized -->
+  <div class="box bpend">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpend" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpend" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpend" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FIFTH ROW:  -webkit-box-pack: justify -->
+  <!-- intrinsically sized -->
+  <div class="box bpjustify">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpjustify" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpjustify" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpjustify" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-pack-vert-1-ref.html

@@ -0,0 +1,151 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Reference
+  </title>
+  <style>
+    .box {
+      display: flex;
+      flex-direction: column;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+      /* auto width */
+      height: 1em;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+      font-size: 50%;
+      width: 2em;
+      /* auto height */
+    }
+
+    .bpstart   { justify-content: flex-start;    }
+    .bpcenter  { justify-content: center;        }
+    .bpend     { justify-content: flex-end;      }
+    .bpjustify { justify-content: space-between; }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-pack -->
+  <!-- intrinsically sized -->
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- SECOND ROW:  -webkit-box-pack: start -->
+  <!-- intrinsically sized -->
+  <div class="box bpstart">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpstart" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpstart" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpstart" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- THIRD ROW:  -webkit-box-pack: center -->
+  <!-- intrinsically sized -->
+  <div class="box bpcenter">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpcenter" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpcenter" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpcenter" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FOURTH ROW:  -webkit-box-pack: end -->
+  <!-- intrinsically sized -->
+  <div class="box bpend">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpend" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpend" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpend" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FIFTH ROW:  -webkit-box-pack: justify -->
+  <!-- intrinsically sized -->
+  <div class="box bpjustify">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpjustify" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpjustify" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpjustify" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+</body>
+</html>

layout/reftests/webkit-box/webkit-box-pack-vert-1.html

@@ -0,0 +1,152 @@
+<!DOCTYPE html>
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>
+    CSS Test: vertically-oriented "display: -webkit-box" container,
+    with all the various -webkit-box-pack values.
+  </title>
+  <style>
+    .box {
+      display: -webkit-box;
+      -webkit-box-orient: vertical;
+      border: 1px solid black;
+      margin: 5px 20px;
+      float: left; /* For testing in "rows" */
+      font: 10px serif;
+    }
+    .box > *:nth-child(1) {
+      background: turquoise;
+      /* auto width */
+      height: 1em;
+    }
+    .box > *:nth-child(2) {
+      background: salmon;
+      font-size: 50%;
+      width: 2em;
+      /* auto height */
+    }
+
+    .bpstart   { -webkit-box-pack: start;   }
+    .bpcenter  { -webkit-box-pack: center;  }
+    .bpend     { -webkit-box-pack: end;     }
+    .bpjustify { -webkit-box-pack: justify; }
+    br { clear: both; }
+  </style>
+</head>
+<body>
+  <!-- FIRST ROW: Default -webkit-box-pack -->
+  <!-- intrinsically sized -->
+  <div class="box">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- SECOND ROW:  -webkit-box-pack: start -->
+  <!-- intrinsically sized -->
+  <div class="box bpstart">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpstart" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpstart" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpstart" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- THIRD ROW:  -webkit-box-pack: center -->
+  <!-- intrinsically sized -->
+  <div class="box bpcenter">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpcenter" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpcenter" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpcenter" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FOURTH ROW:  -webkit-box-pack: end -->
+  <!-- intrinsically sized -->
+  <div class="box bpend">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpend" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpend" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpend" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+  <!-- FIFTH ROW:  -webkit-box-pack: justify -->
+  <!-- intrinsically sized -->
+  <div class="box bpjustify">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra width -->
+  <div class="box bpjustify" style="width: 36px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height -->
+  <div class="box bpjustify" style="height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+
+  <!-- explicit size, extra height and width -->
+  <div class="box bpjustify" style="width: 36px; height: 40px">
+    <div>a</div><div>b</div>
+  </div>
+  <br>
+
+</body>
+</html>

layout/style/nsCSSDataBlock.cpp

@@ -14,7 +14,6 @@
 #include "CSSVariableImageTable.h"
 #include "mozilla/css/Declaration.h"
 #include "mozilla/css/ImageLoader.h"
-#include "mozilla/Maybe.h"
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/WritingModes.h"
 #include "nsIDocument.h"
@@ -41,50 +40,6 @@ MoveValue(nsCSSValue* aSource, nsCSSValue* aDest)
   return changed;
 }
 
-/**
- * This function maps "-webkit-box-orient" values to "flex-direction" values,
- * for a given writing-mode (taken from aRuleData).
- *
- * Specifically:
- *  - If aBoxOrientVal is an enumerated value (representing a physical axis),
- * then we'll map it to the appropriate logical "flex-direction" value, using
- * the writing mode.  The converted value will be emplace()'d into in the
- * outparam aConvertedValStorage, and we'll return a pointer to that value.
- *  - Otherwise (e.g. if we have "inherit" or "initial"), we won't do any
- * mapping, and we'll directly return the passed-in aBoxOrientVal.
- *
- * Either way, the idea is that our caller can treat the returned value as if
- * it were a value for "flex-direction".
- */
-static const nsCSSValue*
-ConvertBoxOrientToFlexDirection(const nsCSSValue* aBoxOrientVal,
-                                const nsRuleData* aRuleData,
-                                Maybe<nsCSSValue>& aConvertedValStorage)
-{
-  MOZ_ASSERT(aBoxOrientVal, "expecting a non-null value to convert");
-  MOZ_ASSERT(aConvertedValStorage.isNothing(),
-             "expecting outparam for converted-value to be initially empty");
-
-  if (aBoxOrientVal->GetUnit() != eCSSUnit_Enumerated) {
-    // We probably have "inherit" or "initial" -- just return that & have the
-    // caller directly use it as a "flex-direction" value.
-    return aBoxOrientVal;
-  }
-
-  // OK, we have an enumerated value -- "horizontal" or "vertical".
-
-  WritingMode wm(aRuleData->mStyleContext);
-  // In a horizontal writing-mode, "horizontal" maps to "row".
-  // In a vertical writing-mode, "horizontal" maps to "column".
-  bool isRow = wm.IsVertical() !=
-    (aBoxOrientVal->GetIntValue() == NS_STYLE_BOX_ORIENT_HORIZONTAL);
-
-  aConvertedValStorage.emplace(isRow ? NS_STYLE_FLEX_DIRECTION_ROW :
-                                       NS_STYLE_FLEX_DIRECTION_COLUMN,
-                               eCSSUnit_Enumerated);
-  return aConvertedValStorage.ptr();
-}
-
 static bool
 ShouldIgnoreColors(nsRuleData *aRuleData)
 {
@@ -170,32 +125,15 @@ ShouldStartImageLoads(nsRuleData *aRuleData, nsCSSProperty aProperty)
 }
 
 static void
-MapSinglePropertyInto(nsCSSProperty aSrcProp,
+MapSinglePropertyInto(nsCSSProperty aTargetProp,
                       const nsCSSValue* aSrcValue,
-                      nsCSSProperty aTargetProp,
                       nsCSSValue* aTargetValue,
                       nsRuleData* aRuleData)
 {
   MOZ_ASSERT(!nsCSSProps::PropHasFlags(aTargetProp, CSS_PROPERTY_LOGICAL),
              "Can't map into a logical property");
-  MOZ_ASSERT(aSrcProp == aTargetProp ||
-             nsCSSProps::PropHasFlags(aSrcProp, CSS_PROPERTY_LOGICAL),
-             "Source & target property must be the same, except when we're "
-             "doing a logical-to-physical property mapping");
   MOZ_ASSERT(aSrcValue->GetUnit() != eCSSUnit_Null, "oops");
 
-  // Handle logical properties that have custom value-mapping behavior:
-  Maybe<nsCSSValue> convertedVal; // storage for converted value, if needed
-  bool hasCustomValMapping =
-      nsCSSProps::PropHasFlags(aSrcProp,
-                               CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING);
-  if (hasCustomValMapping) {
-    if (aSrcProp == eCSSProperty_webkit_box_orient) {
-      aSrcValue = ConvertBoxOrientToFlexDirection(aSrcValue, aRuleData,
-                                                  convertedVal);
-    }
-  }
-
   // Although aTargetValue is the nsCSSValue we are going to write into,
   // we also look at its value before writing into it.  This is done
   // when aTargetValue is a token stream value, which is the case when we
@@ -234,20 +172,13 @@ MapSinglePropertyInto(nsCSSProperty aSrcProp,
 }
 
 /**
- * If aProperty is a logical property, returns the equivalent physical
+ * If aProperty is a logical property, converts it to the equivalent physical
  * property based on writing mode information obtained from aRuleData's
  * style context.
  */
-static inline nsCSSProperty
+static inline void
-EnsurePhysicalProperty(nsCSSProperty aProperty, nsRuleData* aRuleData)
+EnsurePhysicalProperty(nsCSSProperty& aProperty, nsRuleData* aRuleData)
 {
-  if (!nsCSSProps::PropHasFlags(aProperty, CSS_PROPERTY_LOGICAL)) {
-    return aProperty;
-  }
-
-  bool isSingleProperty =
-      nsCSSProps::PropHasFlags(aProperty,
-                               CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING);
   bool isAxisProperty =
     nsCSSProps::PropHasFlags(aProperty, CSS_PROPERTY_LOGICAL_AXIS);
   bool isBlock =
@@ -255,9 +186,7 @@ EnsurePhysicalProperty(nsCSSProperty aProperty, nsRuleData* aRuleData)
 
   int index;
 
-  if (isSingleProperty) {
+  if (isAxisProperty) {
-    index = 0; // We always map to the same physical property.
-  } else if (isAxisProperty) {
     LogicalAxis logicalAxis = isBlock ? eLogicalAxisBlock : eLogicalAxisInline;
     uint8_t wm = aRuleData->mStyleContext->StyleVisibility()->mWritingMode;
     PhysicalAxis axis =
@@ -295,19 +224,43 @@ EnsurePhysicalProperty(nsCSSProperty aProperty, nsRuleData* aRuleData)
   }
 
   const nsCSSProperty* props = nsCSSProps::LogicalGroup(aProperty);
+  size_t len = isAxisProperty ? 2 : 4;
 #ifdef DEBUG
-  {
-    // Table-length is 1 for single prop, 2 for axis prop, 4 for block prop.
-    size_t len = isSingleProperty ? 1 : (isAxisProperty ? 2 : 4);
     for (size_t i = 0; i < len; i++) {
-      MOZ_ASSERT(props[i] != eCSSProperty_UNKNOWN,
+    MOZ_ASSERT(props[i] != eCSSProperty_UNKNOWN,
-                 "unexpected logical group length");
-    }
-    MOZ_ASSERT(props[len] == eCSSProperty_UNKNOWN,
                "unexpected logical group length");
   }
+  MOZ_ASSERT(props[len] == eCSSProperty_UNKNOWN,
+             "unexpected logical group length");
 #endif
-  return props[index];
+
+  for (size_t i = 0; i < len; i++) {
+    if (aRuleData->ValueFor(props[i])->GetUnit() == eCSSUnit_Null) {
+      // A declaration of one of the logical properties in this logical
+      // group (but maybe not aProperty) would be the winning
+      // declaration in the cascade.  This means that it's reasonably
+      // likely that this logical property could be the winning
+      // declaration in the cascade for some values of writing-mode,
+      // direction, and text-orientation.  (It doesn't mean that for
+      // sure, though.  For example, if this is a block-start logical
+      // property, and all but the bottom physical property were set.
+      // But the common case we want to hit here is logical declarations
+      // that are completely overridden by a shorthand.)
+      //
+      // If this logical property could be the winning declaration in
+      // the cascade for some values of writing-mode, direction, and
+      // text-orientation, then we have to fault the resulting style
+      // struct out of the rule tree.  We can't cache anything on the
+      // rule tree if it depends on data from the style context, since
+      // data cached in the rule tree could be used with a style context
+      // with a different value of the depended-upon data.
+      uint8_t wm = WritingMode(aRuleData->mStyleContext).GetBits();
+      aRuleData->mConditions.SetWritingModeDependency(wm);
+      break;
+    }
+  }
+
+  aProperty = props[index];
 }
 
 void
@@ -327,16 +280,10 @@ nsCSSCompressedDataBlock::MapRuleInfoInto(nsRuleData *aRuleData) const
     nsCSSProperty iProp = PropertyAtIndex(i);
     if (nsCachedStyleData::GetBitForSID(nsCSSProps::kSIDTable[iProp]) &
         aRuleData->mSIDs) {
-      nsCSSProperty physicalProp = EnsurePhysicalProperty(iProp,
+      if (nsCSSProps::PropHasFlags(iProp, CSS_PROPERTY_LOGICAL)) {
-                                                          aRuleData);
+        EnsurePhysicalProperty(iProp, aRuleData);
-      if (physicalProp != iProp) {
-        // We can't cache anything on the rule tree if we use any data from
-        // the style context, since data cached in the rule tree could be
-        // used with a style context with a different value.
-        uint8_t wm = WritingMode(aRuleData->mStyleContext).GetBits();
-        aRuleData->mConditions.SetWritingModeDependency(wm);
       }
-      nsCSSValue* target = aRuleData->ValueFor(physicalProp);
+      nsCSSValue* target = aRuleData->ValueFor(iProp);
       if (target->GetUnit() == eCSSUnit_Null) {
         const nsCSSValue *val = ValueAtIndex(i);
         // In order for variable resolution to have the right information
@@ -348,8 +295,7 @@ nsCSSCompressedDataBlock::MapRuleInfoInto(nsRuleData *aRuleData) const
         if (val->GetUnit() == eCSSUnit_TokenStream) {
           val->GetTokenStreamValue()->mLevel = aRuleData->mLevel;
         }
-        MapSinglePropertyInto(iProp, val, physicalProp, target,
+        MapSinglePropertyInto(iProp, val, target, aRuleData);
-                              aRuleData);
       }
     }
   }
@@ -791,10 +737,9 @@ nsCSSExpandedDataBlock::MapRuleInfoInto(nsCSSProperty aPropID,
   const nsCSSValue* src = PropertyAt(aPropID);
   MOZ_ASSERT(src->GetUnit() != eCSSUnit_Null);
 
-  nsCSSProperty physicalProp = EnsurePhysicalProperty(aPropID, aRuleData);
+  nsCSSProperty physicalProp = aPropID;
-  if (physicalProp != aPropID) {
+  if (nsCSSProps::PropHasFlags(aPropID, CSS_PROPERTY_LOGICAL)) {
-    uint8_t wm = WritingMode(aRuleData->mStyleContext).GetBits();
+    EnsurePhysicalProperty(physicalProp, aRuleData);
-    aRuleData->mConditions.SetWritingModeDependency(wm);
   }
 
   nsCSSValue* dest = aRuleData->ValueFor(physicalProp);
@@ -802,7 +747,7 @@ nsCSSExpandedDataBlock::MapRuleInfoInto(nsCSSProperty aPropID,
              dest->GetTokenStreamValue()->mPropertyID == aPropID);
 
   CSSVariableImageTable::ReplaceAll(aRuleData->mStyleContext, aPropID, [=] {
-    MapSinglePropertyInto(aPropID, src, physicalProp, dest, aRuleData);
+    MapSinglePropertyInto(physicalProp, src, dest, aRuleData);
   });
 }
 

layout/style/nsCSSPropAliasList.h

@@ -296,10 +296,6 @@ CSS_PROP_ALIAS(-webkit-border-bottom-right-radius,
                WebkitBorderBottomRightRadius, // really no dom property
                WEBKIT_PREFIX_PREF)
 
-CSS_PROP_ALIAS(-webkit-appearance,
-               appearance,
-               WebkitAppearance,
-               WEBKIT_PREFIX_PREF)
 CSS_PROP_ALIAS(-webkit-background-clip,
                background_clip,
                WebkitBackgroundClip,
@@ -327,21 +323,33 @@ CSS_PROP_ALIAS(-webkit-box-sizing,
                WebkitBoxSizing,
                WEBKIT_PREFIX_PREF)
 
-// Alias old flexbox properties to modern flexbox pseudo-equivalents:
+// Alias -webkit-box properties to their -moz-box equivalents.
+// (NOTE: Even though they're aliases, in practice these -webkit properties
+// will behave a bit differently from their -moz versions, if they're
+// accompanied by "display:-webkit-box", because we generate a different frame
+// for those two display values.)
 CSS_PROP_ALIAS(-webkit-box-flex,
-               flex_grow,
+               box_flex,
                WebkitBoxFlex,
                WEBKIT_PREFIX_PREF)
 CSS_PROP_ALIAS(-webkit-box-ordinal-group,
-               order,
+               box_ordinal_group,
                WebkitBoxOrdinalGroup,
                WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-box-orient,
+               box_orient,
+               WebkitBoxOrient,
+               WEBKIT_PREFIX_PREF)
+CSS_PROP_ALIAS(-webkit-box-direction,
+               box_direction,
+               WebkitBoxDirection,
+               WEBKIT_PREFIX_PREF)
 CSS_PROP_ALIAS(-webkit-box-align,
-               align_items,
+               box_align,
                WebkitBoxAlign,
                WEBKIT_PREFIX_PREF)
 CSS_PROP_ALIAS(-webkit-box-pack,
-               justify_content,
+               box_pack,
                WebkitBoxPack,
                WEBKIT_PREFIX_PREF)
 

layout/style/nsCSSPropList.h

@@ -1330,22 +1330,6 @@ CSS_PROP_XUL(
     kBoxOrientKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_None) // XXX bug 3935
-/* We treat -webkit-box-orient as a writing-mode-aware logical alias
- * for "flex-direction": */
-CSS_PROP_LOGICAL(
-    -webkit-box-orient,
-    webkit_box_orient,
-    WebkitBoxOrient,
-    CSS_PROPERTY_PARSE_VALUE |
-      CSS_PROPERTY_LOGICAL |
-      CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING,
-    "layout.css.prefixes.webkit",
-    VARIANT_HK,
-    kBoxOrientKTable,
-    WebkitBoxOrient,
-    Position,
-    CSS_PROP_NO_OFFSET,
-    eStyleAnimType_None)
 CSS_PROP_XUL(
     -moz-box-pack,
     box_pack,

layout/style/nsCSSPropLogicalGroupList.h

@@ -44,17 +44,6 @@
 //     defined in nCSSProps.cpp named g<name_>LogicalGroupTable
 //     containing the two physical properties in vertical/horizontal
 //     order, followed by an nsCSSProperty_UNKNOWN entry.
-//
-//   CSS_PROP_LOGICAL_GROUP_SINGLE(name_)
-//     Defines a logical property group in which the logical property always
-//     maps to the same physical property. For such properties, the
-//     "logicalness" is in the value-mapping, not in the property-mapping.  For
-//     example, the logical property "-webkit-box-orient" is always mapped to
-//     "flex-direction", but its values ("horizontal", "vertical") map to
-//     different flex-direction values ("row", "column") depending on the
-//     writing-mode.  A table must be defined in nsCSSProps.cpp named
-//     g<name_>LogicalGroupTable containing the one physical property,
-//     followed by an nsCSSProperty_UNKNOWN entry.
 
 CSS_PROP_LOGICAL_GROUP_SHORTHAND(BorderColor)
 CSS_PROP_LOGICAL_GROUP_SHORTHAND(BorderStyle)
@@ -65,4 +54,3 @@ CSS_PROP_LOGICAL_GROUP_BOX(Offset)
 CSS_PROP_LOGICAL_GROUP_SHORTHAND(Padding)
 CSS_PROP_LOGICAL_GROUP_AXIS(MinSize)
 CSS_PROP_LOGICAL_GROUP_AXIS(Size)
-CSS_PROP_LOGICAL_GROUP_SINGLE(WebkitBoxOrient)

layout/style/nsCSSProperty.h

@@ -103,13 +103,10 @@ enum nsCSSPropertyLogicalGroup {
   eCSSPropertyLogicalGroup_##name_,
 #define CSS_PROP_LOGICAL_GROUP_BOX(name_) \
   eCSSPropertyLogicalGroup_##name_,
-#define CSS_PROP_LOGICAL_GROUP_SINGLE(name_) \
-  eCSSPropertyLogicalGroup_##name_,
 #define CSS_PROP_LOGICAL_GROUP_SHORTHAND(name_) \
   eCSSPropertyLogicalGroup_##name_,
 #include "nsCSSPropLogicalGroupList.h"
 #undef CSS_PROP_LOGICAL_GROUP_SHORTHAND
-#undef CSS_PROP_LOGICAL_GROUP_SINGLE
 #undef CSS_PROP_LOGICAL_GROUP_BOX
 #undef CSS_PROP_LOGICAL_GROUP_AXIS
   eCSSPropertyLogicalGroup_COUNT

layout/style/nsCSSProps.cpp

@@ -3026,19 +3026,12 @@ static const nsCSSProperty gSizeLogicalGroupTable[] = {
   eCSSProperty_UNKNOWN
 };
 
-static const nsCSSProperty gWebkitBoxOrientLogicalGroupTable[] = {
-  eCSSProperty_flex_direction,
-  eCSSProperty_UNKNOWN
-};
-
 const nsCSSProperty* const
 nsCSSProps::kLogicalGroupTable[eCSSPropertyLogicalGroup_COUNT] = {
 #define CSS_PROP_LOGICAL_GROUP_SHORTHAND(id_) g##id_##SubpropTable,
 #define CSS_PROP_LOGICAL_GROUP_AXIS(name_) g##name_##LogicalGroupTable,
 #define CSS_PROP_LOGICAL_GROUP_BOX(name_) g##name_##LogicalGroupTable,
-#define CSS_PROP_LOGICAL_GROUP_SINGLE(name_) g##name_##LogicalGroupTable,
 #include "nsCSSPropLogicalGroupList.h"
-#undef CSS_PROP_LOGICAL_GROUP_SINGLE
 #undef CSS_PROP_LOGICAL_GROUP_BOX
 #undef CSS_PROP_LOGICAL_GROUP_AXIS
 #undef CSS_PROP_LOGICAL_GROUP_SHORTHAND
@@ -3339,10 +3332,7 @@ nsCSSProps::gPropertyUseCounter[eCSSProperty_COUNT_no_shorthands] = {
                 "the CSS_PROPERTY_LOGICAL_BLOCK_AXIS flag");                \
   static_assert(!((flags_) & CSS_PROPERTY_LOGICAL_END_EDGE),                \
                 "only properties defined with CSS_PROP_LOGICAL can use "    \
-                "the CSS_PROPERTY_LOGICAL_END_EDGE flag");                  \
+                "the CSS_PROPERTY_LOGICAL_END_EDGE flag");
-  static_assert(!((flags_) & CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING),\
-                "only properties defined with CSS_PROP_LOGICAL can use "    \
-                "the CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING flag");
 #define CSS_PROP_LOGICAL(name_, id_, method_, flags_, pref_, parsevariant_, \
                          kwtable_, group_, stylestruct_,                    \
                          stylestructoffset_, animtype_)                     \
@@ -3355,21 +3345,7 @@ nsCSSProps::gPropertyUseCounter[eCSSProperty_COUNT_no_shorthands] = {
   static_assert(!(((flags_) & CSS_PROPERTY_LOGICAL_AXIS) &&                 \
                   ((flags_) & CSS_PROPERTY_LOGICAL_END_EDGE)),              \
                 "CSS_PROPERTY_LOGICAL_END_EDGE makes no sense when used "   \
-                "with CSS_PROPERTY_LOGICAL_AXIS");                          \
+                "with CSS_PROPERTY_LOGICAL_AXIS");
-  /* Make sure CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING isn't used */  \
-  /* with other mutually-exclusive flags: */                                \
-  static_assert(!(((flags_) & CSS_PROPERTY_LOGICAL_AXIS) &&                 \
-                  ((flags_) & CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING)),\
-                "CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING makes no "   \
-                "sense when used with CSS_PROPERTY_LOGICAL_AXIS");          \
-  static_assert(!(((flags_) & CSS_PROPERTY_LOGICAL_BLOCK_AXIS) &&           \
-                  ((flags_) & CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING)),\
-                "CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING makes no "   \
-                "sense when used with CSS_PROPERTY_LOGICAL_BLOCK_AXIS");    \
-  static_assert(!(((flags_) & CSS_PROPERTY_LOGICAL_END_EDGE) &&             \
-                  ((flags_) & CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING)),\
-                "CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING makes no "   \
-                "sense when used with CSS_PROPERTY_LOGICAL_END_EDGE");
 #include "nsCSSPropList.h"
 #undef CSS_PROP_LOGICAL
 #undef CSS_PROP

layout/style/nsCSSProps.h

@@ -226,6 +226,10 @@ static_assert((CSS_PROPERTY_PARSE_PROPERTY_MASK &
 //   wrapped in "#ifndef CSS_PROP_LIST_EXCLUDE_INTERNAL".
 // Note that, these flags have no effect on the use of aliases of this
 // property.
+// Furthermore, for the purposes of animation (including triggering
+// transitions) these flags are ignored. That is, if the property is disabled
+// by a pref, we will *not* run animations or transitions on it even in
+// UA sheets or chrome.
 #define CSS_PROPERTY_ENABLED_MASK                 (3<<22)
 #define CSS_PROPERTY_ENABLED_IN_UA_SHEETS         (1<<22)
 #define CSS_PROPERTY_ENABLED_IN_CHROME            (1<<23)
@@ -250,26 +254,20 @@ static_assert((CSS_PROPERTY_PARSE_PROPERTY_MASK &
 // margin-block-start or margin-inline-start).
 #define CSS_PROPERTY_LOGICAL_END_EDGE             (1<<26)
 
-// This property is a logical property which always maps to the same physical
-// property, and its values have some custom processing when being mapped to
-// the physical property's values.  Must not be used in conjunction with
-// CSS_PROPERTY_LOGICAL_{AXIS,BLOCK_AXIS,END_EDGE}.
-#define CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING (1<<27)
-
 // This property can be animated on the compositor.
-#define CSS_PROPERTY_CAN_ANIMATE_ON_COMPOSITOR    (1<<28)
+#define CSS_PROPERTY_CAN_ANIMATE_ON_COMPOSITOR    (1<<27)
 
 // This property is an internal property that is not represented
 // in the DOM.  Properties with this flag must be defined in an #ifndef
 // CSS_PROP_LIST_EXCLUDE_INTERNAL section of nsCSSPropList.h.
-#define CSS_PROPERTY_INTERNAL                     (1<<29)
+#define CSS_PROPERTY_INTERNAL                     (1<<28)
 
 // This property has values that can establish a containing block for
 // fixed positioned and absolutely positioned elements.
 // This should be set for any properties that can cause an element to be
 // such a containing block, as implemented in
 // nsStyleDisplay::IsFixedPosContainingBlock.
-#define CSS_PROPERTY_FIXPOS_CB                    (1<<30)
+#define CSS_PROPERTY_FIXPOS_CB                    (1<<29)
 
 // This property has values that can establish a containing block for
 // absolutely positioned elements.
@@ -278,10 +276,7 @@ static_assert((CSS_PROPERTY_PARSE_PROPERTY_MASK &
 // nsStyleDisplay::IsAbsPosContainingBlock.
 // It does not need to be set for properties that also have
 // CSS_PROPERTY_FIXPOS_CB set.
-#define CSS_PROPERTY_ABSPOS_CB                    (1u<<31)
+#define CSS_PROPERTY_ABSPOS_CB                    (1<<30)
-
-// NOTE: Before adding any new CSS_PROPERTY_* flags here, we'll need to
-// upgrade kFlagsTable to 64-bits -- see bug 1231384.
 
 /**
  * Types of animatable values.
@@ -555,11 +550,8 @@ public:
    * by the sentinel.
    *
    * When called with a property that has the CSS_PROPERTY_LOGICAL_AXIS
-   * flag, the returned array will have two values preceding the sentinel.
+   * flag, the returned array will have two values preceding the sentinel;
-   * When called with a property that has the
+   * otherwise it will have four.
-   * CSS_PROPERTY_LOGICAL_SINGLE_CUSTOM_VALMAPPING flag, the returned array
-   * will have one value preceding the sentinel.
-   * Otherwise it will have four values preceding the sentinel.
    *
    * (Note that the running time of this function is proportional to the
    * number of logical longhand properties that exist.  If we start

layout/style/nsCSSRuleProcessor.cpp

@@ -3209,7 +3209,7 @@ nsCSSRuleProcessor::ClearRuleCascades()
 
   // We rely on our caller (perhaps indirectly) to do something that
   // will rebuild style data and the user font set (either
-  // nsIPresShell::ReconstructStyleData or
+  // nsIPresShell::RestyleForCSSRuleChanges or
   // nsPresContext::RebuildAllStyleData).
   RuleCascadeData *data = mRuleCascades;
   mRuleCascades = nullptr;

layout/style/nsRuleNode.cpp

@@ -5303,7 +5303,7 @@ nsRuleNode::ComputeDisplayData(void* aStartStruct,
                          display, parentDisplay, aRuleData,
                          conditions);
 
-  display->mTransitions.SetLength(numTransitions);
+  display->mTransitions.SetLengthNonZero(numTransitions);
 
   FOR_ALL_TRANSITION_PROPS(p) {
     const TransitionPropInfo& i = transitionPropInfo[p];
@@ -5460,7 +5460,7 @@ nsRuleNode::ComputeDisplayData(void* aStartStruct,
                          display, parentDisplay, aRuleData,
                          conditions);
 
-  display->mAnimations.SetLength(numAnimations);
+  display->mAnimations.SetLengthNonZero(numAnimations);
 
   FOR_ALL_ANIMATION_PROPS(p) {
     const TransitionPropInfo& i = animationPropInfo[p];
@@ -6779,8 +6779,8 @@ template <class ComputedValueItem>
 static void
 SetImageLayerList(nsStyleContext* aStyleContext,
                   const nsCSSValue& aValue,
-                  AutoTArray< nsStyleImageLayers::Layer, 1> &aLayers,
+                  nsStyleAutoArray<nsStyleImageLayers::Layer>& aLayers,
-                  const AutoTArray<nsStyleImageLayers::Layer, 1> &aParentLayers,
+                  const nsStyleAutoArray<nsStyleImageLayers::Layer>& aParentLayers,
                   ComputedValueItem nsStyleImageLayers::Layer::* aResultLocation,
                   ComputedValueItem aInitialValue,
                   uint32_t aParentItemCount,
@@ -6844,9 +6844,8 @@ template <class ComputedValueItem>
 static void
 SetImageLayerPairList(nsStyleContext* aStyleContext,
                       const nsCSSValue& aValue,
-                      AutoTArray< nsStyleImageLayers::Layer, 1> &aLayers,
+                      nsStyleAutoArray<nsStyleImageLayers::Layer>& aLayers,
-                      const AutoTArray<nsStyleImageLayers::Layer, 1>
+                      const nsStyleAutoArray<nsStyleImageLayers::Layer>& aParentLayers,
-                                                                 &aParentLayers,
                       ComputedValueItem nsStyleImageLayers::Layer::*
                                                                 aResultLocation,
                       ComputedValueItem aInitialValue,
@@ -6911,7 +6910,8 @@ SetImageLayerPairList(nsStyleContext* aStyleContext,
 
 template <class ComputedValueItem>
 static void
-FillBackgroundList(AutoTArray< nsStyleImageLayers::Layer, 1> &aLayers,
+FillBackgroundList(
+    nsStyleAutoArray<nsStyleImageLayers::Layer>& aLayers,
     ComputedValueItem nsStyleImageLayers::Layer::* aResultLocation,
     uint32_t aItemCount, uint32_t aFillCount)
 {
@@ -7033,7 +7033,7 @@ nsRuleNode::ComputeBackgroundData(void* aStartStruct,
   if (rebuild) {
     // Delete any extra items.  We need to keep layers in which any
     // property was specified.
-    bg->mImage.mLayers.TruncateLength(maxItemCount);
+    bg->mImage.mLayers.TruncateLengthNonZero(maxItemCount);
 
     uint32_t fillCount = bg->mImage.mImageCount;
     FillBackgroundList(bg->mImage.mLayers,
@@ -9852,7 +9852,7 @@ nsRuleNode::ComputeSVGResetData(void* aStartStruct,
   if (rebuild) {
     // Delete any extra items.  We need to keep layers in which any
     // property was specified.
-    svgReset->mMask.mLayers.TruncateLength(maxItemCount);
+    svgReset->mMask.mLayers.TruncateLengthNonZero(maxItemCount);
 
     uint32_t fillCount = svgReset->mMask.mImageCount;
 

layout/style/nsStyleStruct.cpp

@@ -2317,10 +2317,9 @@ nsStyleImageLayers::nsStyleImageLayers()
   , mMaskModeCount(1)
   , mBlendModeCount(1)
   , mCompositeCount(1)
+  , mLayers(nsStyleAutoArray<Layer>::WITH_SINGLE_INITIAL_ELEMENT)
 {
   MOZ_COUNT_CTOR(nsStyleImageLayers);
-  mLayers.AppendElement();
-  NS_ASSERTION(mLayers.Length() == 1, "auto array must have room for 1 element");
 }
 
 nsStyleImageLayers::nsStyleImageLayers(const nsStyleImageLayers &aSource)
@@ -2388,7 +2387,8 @@ nsStyleImageLayers::CalcDifference(const nsStyleImageLayers& aOther) const
     return hint;
   }
 
-  if (mBlendModeCount != aOther.mBlendModeCount ||
+  if (mAttachmentCount != aOther.mAttachmentCount ||
+      mBlendModeCount != aOther.mBlendModeCount ||
       mClipCount != aOther.mClipCount ||
       mCompositeCount != aOther.mCompositeCount ||
       mMaskModeCount != aOther.mMaskModeCount ||
@@ -2406,7 +2406,12 @@ bool
 nsStyleImageLayers::HasLayerWithImage() const
 {
   for (uint32_t i = 0; i < mImageCount; i++) {
-    if (mLayers[i].mSourceURI) {
+    // mLayers[i].mSourceURI can be nullptr if mask-image prop value is
+    // <element-reference> or <gradient>
+    // mLayers[i].mImage can be empty if mask-image prop value is a reference
+    // to SVG mask element.
+    // So we need to test both mSourceURI and mImage.
+    if (mLayers[i].mSourceURI || !mLayers[i].mImage.IsEmpty()) {
       return true;
     }
   }
@@ -2832,6 +2837,8 @@ mozilla::StyleAnimation::operator==(const mozilla::StyleAnimation& aOther) const
 
 nsStyleDisplay::nsStyleDisplay(StyleStructContext aContext)
   : mWillChangeBitField(0)
+  , mTransitions(nsStyleAutoArray<StyleTransition>::WITH_SINGLE_INITIAL_ELEMENT)
+  , mAnimations(nsStyleAutoArray<StyleAnimation>::WITH_SINGLE_INITIAL_ELEMENT)
 {
   MOZ_COUNT_CTOR(nsStyleDisplay);
   mAppearance = NS_THEME_NONE;
@@ -2872,18 +2879,12 @@ nsStyleDisplay::nsStyleDisplay(StyleStructContext aContext)
   // Initial value for mScrollSnapDestination is "0px 0px"
   mScrollSnapDestination.SetInitialZeroValues();
 
-  mTransitions.AppendElement();
-  MOZ_ASSERT(mTransitions.Length() == 1,
-             "appending within auto buffer should never fail");
   mTransitions[0].SetInitialValues();
   mTransitionTimingFunctionCount = 1;
   mTransitionDurationCount = 1;
   mTransitionDelayCount = 1;
   mTransitionPropertyCount = 1;
 
-  mAnimations.AppendElement();
-  MOZ_ASSERT(mAnimations.Length() == 1,
-             "appending within auto buffer should never fail");
   mAnimations[0].SetInitialValues();
   mAnimationTimingFunctionCount = 1;
   mAnimationDurationCount = 1;

layout/style/nsStyleStruct.h

@@ -152,7 +152,7 @@ static_assert(offsetof(nsRect_Simple, width) == offsetof(nsRect, width), "Wrong
 static_assert(offsetof(nsRect_Simple, height) == offsetof(nsRect, height), "Wrong nsRect_Simple member alignment");
 
 // The lifetime of these objects is managed by the presshell's arena.
-struct nsStyleFont
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleFont
 {
   nsStyleFont(const nsFont& aFont, StyleStructContext aContext);
   nsStyleFont(const nsStyleFont& aStyleFont);
@@ -421,7 +421,7 @@ private:
 #endif
 };
 
-struct nsStyleColor
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleColor
 {
   explicit nsStyleColor(StyleStructContext aContext);
   nsStyleColor(const nsStyleColor& aOther);
@@ -455,6 +455,65 @@ struct nsStyleColor
   nscolor mColor;                 // [inherited]
 };
 
+/**
+ * An array of objects, similar to AutoTArray<T,1> but which is memmovable. It
+ * always has length >= 1.
+ */
+template<typename T>
+class nsStyleAutoArray
+{
+public:
+  // This constructor places a single element in mFirstElement.
+  enum WithSingleInitialElement { WITH_SINGLE_INITIAL_ELEMENT };
+  explicit nsStyleAutoArray(WithSingleInitialElement) {}
+  nsStyleAutoArray(const nsStyleAutoArray& aOther) { *this = aOther; }
+  nsStyleAutoArray& operator=(const nsStyleAutoArray& aOther) {
+    mFirstElement = aOther.mFirstElement;
+    mOtherElements = aOther.mOtherElements;
+    return *this;
+  }
+
+  bool operator==(const nsStyleAutoArray& aOther) const {
+    return Length() == aOther.Length() &&
+           mFirstElement == aOther.mFirstElement &&
+           mOtherElements == aOther.mOtherElements;
+  }
+  bool operator!=(const nsStyleAutoArray& aOther) const {
+    return !(*this == aOther);
+  }
+
+  size_t Length() const {
+    return mOtherElements.Length() + 1;
+  }
+  const T& operator[](size_t aIndex) const {
+    return aIndex == 0 ? mFirstElement : mOtherElements[aIndex - 1];
+  }
+  T& operator[](size_t aIndex) {
+    return aIndex == 0 ? mFirstElement : mOtherElements[aIndex - 1];
+  }
+
+  void EnsureLengthAtLeast(size_t aMinLen) {
+    if (aMinLen > 0) {
+      mOtherElements.EnsureLengthAtLeast(aMinLen - 1);
+    }
+  }
+
+  void SetLengthNonZero(size_t aNewLen) {
+    MOZ_ASSERT(aNewLen > 0);
+    mOtherElements.SetLength(aNewLen - 1);
+  }
+
+  void TruncateLengthNonZero(size_t aNewLen) {
+    MOZ_ASSERT(aNewLen > 0);
+    MOZ_ASSERT(aNewLen <= Length());
+    mOtherElements.TruncateLength(aNewLen - 1);
+  }
+
+private:
+  T mFirstElement;
+  nsTArray<T> mOtherElements;
+};
+
 struct nsStyleImageLayers {
   nsStyleImageLayers();
   nsStyleImageLayers(const nsStyleImageLayers &aSource);
@@ -695,7 +754,7 @@ struct nsStyleImageLayers {
   // layer.  In layers below the bottom layer, properties will be
   // uninitialized unless their count, above, indicates that they are
   // present.
-  AutoTArray<Layer, 1> mLayers;
+  nsStyleAutoArray<Layer> mLayers;
 
   const Layer& BottomLayer() const { return mLayers[mImageCount - 1]; }
 
@@ -724,7 +783,7 @@ struct nsStyleImageLayers {
     for (uint32_t var_ = (start_) + 1; var_-- != (uint32_t)((start_) + 1 - (count_)); )
 };
 
-struct nsStyleBackground {
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleBackground {
   explicit nsStyleBackground(StyleStructContext aContext);
   nsStyleBackground(const nsStyleBackground& aOther);
   ~nsStyleBackground();
@@ -777,7 +836,7 @@ struct nsStyleBackground {
 #define NS_SPACING_BORDER   2
 
 
-struct nsStyleMargin
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleMargin
 {
   explicit nsStyleMargin(StyleStructContext aContext);
   nsStyleMargin(const nsStyleMargin& aMargin);
@@ -823,7 +882,7 @@ protected:
 };
 
 
-struct nsStylePadding
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStylePadding
 {
   explicit nsStylePadding(StyleStructContext aContext);
   nsStylePadding(const nsStylePadding& aPadding);
@@ -1026,7 +1085,7 @@ static bool IsVisibleBorderStyle(uint8_t aStyle)
           aStyle != NS_STYLE_BORDER_STYLE_HIDDEN);
 }
 
-struct nsStyleBorder
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleBorder
 {
   explicit nsStyleBorder(StyleStructContext aContext);
   nsStyleBorder(const nsStyleBorder& aBorder);
@@ -1253,7 +1312,7 @@ private:
 };
 
 
-struct nsStyleOutline
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleOutline
 {
   explicit nsStyleOutline(StyleStructContext aContext);
   nsStyleOutline(const nsStyleOutline& aOutline);
@@ -1364,7 +1423,7 @@ private:
   ~nsStyleQuoteValues() {}
 };
 
-struct nsStyleList
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleList
 {
   explicit nsStyleList(StyleStructContext aContext);
   nsStyleList(const nsStyleList& aStyleList);
@@ -1570,7 +1629,7 @@ struct nsStyleTextOverflow
   bool mLogicalDirections;  // true when only one value was specified
 };
 
-struct nsStyleTextReset
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleTextReset
 {
   explicit nsStyleTextReset(StyleStructContext aContext);
   nsStyleTextReset(const nsStyleTextReset& aOther);
@@ -1655,7 +1714,7 @@ protected:
   nscolor mTextDecorationColor;         // [reset] the colors to use for a decoration lines, not used at currentColor
 };
 
-struct nsStyleText
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleText
 {
   explicit nsStyleText(StyleStructContext aContext);
   nsStyleText(const nsStyleText& aOther);
@@ -1872,7 +1931,7 @@ protected:
   uint8_t mOrientation;
 };
 
-struct nsStyleVisibility
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleVisibility
 {
   explicit nsStyleVisibility(StyleStructContext aContext);
   nsStyleVisibility(const nsStyleVisibility& aVisibility);
@@ -2153,7 +2212,7 @@ private:
 
 } // namespace mozilla
 
-struct nsStyleDisplay
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleDisplay
 {
   explicit nsStyleDisplay(StyleStructContext aContext);
   nsStyleDisplay(const nsStyleDisplay& aOther);
@@ -2224,7 +2283,7 @@ struct nsStyleDisplay
                                 // match mWillChange. Also tracks if any of the
                                 // properties in the will-change list require
                                 // a stacking context.
-  AutoTArray<nsString, 1> mWillChange;
+  nsTArray<nsString> mWillChange;
 
   uint8_t mTouchAction;         // [reset] see nsStyleConsts.h
   uint8_t mScrollBehavior;      // [reset] see nsStyleConsts.h NS_STYLE_SCROLL_BEHAVIOR_*
@@ -2249,7 +2308,7 @@ struct nsStyleDisplay
 
   nsStyleCoord mVerticalAlign;  // [reset] coord, percent, calc, enum (see nsStyleConsts.h)
 
-  AutoTArray<mozilla::StyleTransition, 1> mTransitions; // [reset]
+  nsStyleAutoArray<mozilla::StyleTransition> mTransitions; // [reset]
   // The number of elements in mTransitions that are not from repeating
   // a list due to another property being longer.
   uint32_t mTransitionTimingFunctionCount,
@@ -2257,7 +2316,7 @@ struct nsStyleDisplay
            mTransitionDelayCount,
            mTransitionPropertyCount;
 
-  AutoTArray<mozilla::StyleAnimation, 1> mAnimations; // [reset]
+  nsStyleAutoArray<mozilla::StyleAnimation> mAnimations; // [reset]
   // The number of elements in mAnimations that are not from repeating
   // a list due to another property being longer.
   uint32_t mAnimationTimingFunctionCount,
@@ -2425,7 +2484,7 @@ struct nsStyleDisplay
   inline uint8_t PhysicalBreakType(mozilla::WritingMode aWM) const;
 };
 
-struct nsStyleTable
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleTable
 {
   explicit nsStyleTable(StyleStructContext aContext);
   nsStyleTable(const nsStyleTable& aOther);
@@ -2536,7 +2595,7 @@ struct nsStyleGridTemplate
   }
 };
 
-struct nsStylePosition
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStylePosition
 {
   explicit nsStylePosition(StyleStructContext aContext);
   nsStylePosition(const nsStylePosition& aOther);
@@ -2730,7 +2789,7 @@ private:
 };
 
 
-struct nsStyleTableBorder
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleTableBorder
 {
   explicit nsStyleTableBorder(StyleStructContext aContext);
   nsStyleTableBorder(const nsStyleTableBorder& aOther);
@@ -2830,7 +2889,7 @@ struct nsStyleCounterData
 
 #define DELETE_ARRAY_IF(array)  if (array) { delete[] array; array = nullptr; }
 
-struct nsStyleContent
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleContent
 {
   explicit nsStyleContent(StyleStructContext aContext);
   nsStyleContent(const nsStyleContent& aContent);
@@ -2941,7 +3000,7 @@ protected:
   uint32_t            mResetCount;
 };
 
-struct nsStyleUIReset
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleUIReset
 {
   explicit nsStyleUIReset(StyleStructContext aContext);
   nsStyleUIReset(const nsStyleUIReset& aOther);
@@ -3007,7 +3066,7 @@ private:
   nsCOMPtr<imgIRequest> mImage;
 };
 
-struct nsStyleUserInterface
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleUserInterface
 {
   explicit nsStyleUserInterface(StyleStructContext aContext);
   nsStyleUserInterface(const nsStyleUserInterface& aOther);
@@ -3058,7 +3117,7 @@ struct nsStyleUserInterface
   inline uint8_t GetEffectivePointerEvents(nsIFrame* aFrame) const;
 };
 
-struct nsStyleXUL
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleXUL
 {
   explicit nsStyleXUL(StyleStructContext aContext);
   nsStyleXUL(const nsStyleXUL& aSource);
@@ -3096,7 +3155,7 @@ struct nsStyleXUL
   bool          mStretchStack;          // [reset] see nsStyleConsts.h
 };
 
-struct nsStyleColumn
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleColumn
 {
   explicit nsStyleColumn(StyleStructContext aContext);
   nsStyleColumn(const nsStyleColumn& aSource);
@@ -3191,7 +3250,7 @@ struct nsStyleSVGPaint
   }
 };
 
-struct nsStyleSVG
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleSVG
 {
   explicit nsStyleSVG(StyleStructContext aContext);
   nsStyleSVG(const nsStyleSVG& aSource);
@@ -3477,7 +3536,7 @@ struct nsTArray_CopyChooser<nsStyleFilter>
   typedef nsTArray_CopyWithConstructors<nsStyleFilter> Type;
 };
 
-struct nsStyleSVGReset
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleSVGReset
 {
   explicit nsStyleSVGReset(StyleStructContext aContext);
   nsStyleSVGReset(const nsStyleSVGReset& aSource);
@@ -3527,7 +3586,7 @@ struct nsStyleSVGReset
   uint8_t          mMaskType;         // [reset] see nsStyleConsts.h
 };
 
-struct nsStyleVariables
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleVariables
 {
   explicit nsStyleVariables(StyleStructContext aContext);
   nsStyleVariables(const nsStyleVariables& aSource);
@@ -3557,7 +3616,7 @@ struct nsStyleVariables
   mozilla::CSSVariableValues mVariables;
 };
 
-struct nsStyleEffects
+struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleEffects
 {
   explicit nsStyleEffects(StyleStructContext aContext);
   nsStyleEffects(const nsStyleEffects& aSource);

layout/style/nsStyleTransformMatrix.cpp

@@ -639,6 +639,7 @@ MatrixForTransformFunction(Matrix4x4& aMatrix,
     break;
   case eCSSKeyword_rotatez:
     *aContains3dTransform = true;
+    MOZ_FALLTHROUGH;
   case eCSSKeyword_rotate:
     ProcessRotateZ(aMatrix, aData);
     break;

layout/style/nsTransitionManager.cpp

@@ -63,13 +63,11 @@ ElementPropertyTransition::CurrentValuePortion() const
 
   MOZ_ASSERT(!computedTiming.mProgress.IsNull(),
              "Got a null progress for a fill mode of 'both'");
-  MOZ_ASSERT(mProperties.Length() == 1,
+  MOZ_ASSERT(mFrames.Length() == 2,
-             "Should have one animation property for a transition");
+             "Should have two animation frames for a transition");
-  MOZ_ASSERT(mProperties[0].mSegments.Length() == 1,
+  return ComputedTimingFunction::GetPortion(mFrames[0].mTimingFunction,
-             "Animation property should have one segment for a transition");
+                                            computedTiming.mProgress.Value(),
-  return ComputedTimingFunction::GetPortion(
+                                            computedTiming.mBeforeFlag);
-           mProperties[0].mSegments[0].mTimingFunction,
-           computedTiming.mProgress.Value(), computedTiming.mBeforeFlag);
 }
 
 ////////////////////////// CSSTransition ////////////////////////////
@@ -135,16 +133,6 @@ CSSTransition::QueueEvents()
   mOwningElement.GetElement(owningElement, owningPseudoType);
   MOZ_ASSERT(owningElement, "Owning element should be set");
 
-  // Do not queue any event for disabled properties. This could happen
-  // if the property has a default value which derives value from other
-  // property, e.g. color.
-  nsCSSProperty property = TransitionProperty();
-  if (!nsCSSProps::IsEnabled(property, nsCSSProps::eEnabledForAllContent) &&
-      (!nsContentUtils::IsSystemPrincipal(owningElement->NodePrincipal()) ||
-       !nsCSSProps::IsEnabled(property, nsCSSProps::eEnabledInChrome))) {
-    return;
-  }
-
   nsPresContext* presContext = mOwningElement.GetRenderedPresContext();
   if (!presContext) {
     return;
@@ -152,7 +140,7 @@ CSSTransition::QueueEvents()
 
   nsTransitionManager* manager = presContext->TransitionManager();
   manager->QueueEvent(TransitionEventInfo(owningElement, owningPseudoType,
-                                          property,
+                                          TransitionProperty(),
                                           mEffect->GetComputedTiming()
                                             .mDuration,
                                           AnimationTimeToTimeStamp(EffectEnd()),
@@ -178,6 +166,17 @@ CSSTransition::TransitionProperty() const
   return effect->AsTransition()->TransitionProperty();
 }
 
+StyleAnimationValue
+CSSTransition::ToValue() const
+{
+  // FIXME: Once we support replacing/removing the effect (bug 1049975)
+  // the following assertion will no longer hold.
+  dom::KeyframeEffectReadOnly* effect = GetEffect();
+  MOZ_ASSERT(effect && effect->AsTransition(),
+             "Transition should have a transition effect");
+  return effect->AsTransition()->ToValue();
+}
+
 bool
 CSSTransition::HasLowerCompositeOrderThan(const CSSTransition& aOther) const
 {
@@ -335,131 +334,12 @@ nsTransitionManager::StyleContextChanged(dom::Element *aElement,
 
   nsAutoAnimationMutationBatch mb(aElement->OwnerDoc());
 
-  // Per http://lists.w3.org/Archives/Public/www-style/2009Aug/0109.html
+  DebugOnly<bool> startedAny = false;
-  // I'll consider only the transitions from the number of items in
+  // We don't have to update transitions if display:none, although we will
-  // 'transition-property' on down, and later ones will override earlier
+  // cancel them after restyling.
-  // ones (tracked using |whichStarted|).
+  if (!afterChangeStyle->IsInDisplayNoneSubtree()) {
-  bool startedAny = false;
+    startedAny = UpdateTransitions(disp, aElement, collection,
-  nsCSSPropertySet whichStarted;
+                                   aOldStyleContext, afterChangeStyle);
-  for (uint32_t i = disp->mTransitionPropertyCount; i-- != 0; ) {
-    const StyleTransition& t = disp->mTransitions[i];
-    // Check the combined duration (combination of delay and duration)
-    // first, since it defaults to zero, which means we can ignore the
-    // transition.
-    if (t.GetCombinedDuration() > 0.0f) {
-      // We might have something to transition.  See if any of the
-      // properties in question changed and are animatable.
-      // FIXME: Would be good to find a way to share code between this
-      // interpretation of transition-property and the one below.
-      nsCSSProperty property = t.GetProperty();
-      if (property == eCSSPropertyExtra_no_properties ||
-          property == eCSSPropertyExtra_variable ||
-          property == eCSSProperty_UNKNOWN) {
-        // Nothing to do, but need to exclude this from cases below.
-      } else if (property == eCSSPropertyExtra_all_properties) {
-        for (nsCSSProperty p = nsCSSProperty(0);
-             p < eCSSProperty_COUNT_no_shorthands;
-             p = nsCSSProperty(p + 1)) {
-          ConsiderStartingTransition(p, t, aElement, collection,
-                                     aOldStyleContext, afterChangeStyle,
-                                     &startedAny, &whichStarted);
-        }
-      } else if (nsCSSProps::IsShorthand(property)) {
-        CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(
-            subprop, property, nsCSSProps::eEnabledForAllContent) {
-          ConsiderStartingTransition(*subprop, t, aElement, collection,
-                                     aOldStyleContext, afterChangeStyle,
-                                     &startedAny, &whichStarted);
-        }
-      } else {
-        ConsiderStartingTransition(property, t, aElement, collection,
-                                   aOldStyleContext, afterChangeStyle,
-                                   &startedAny, &whichStarted);
-      }
-    }
-  }
-
-  // Stop any transitions for properties that are no longer in
-  // 'transition-property', including finished transitions.
-  // Also stop any transitions (and remove any finished transitions)
-  // for properties that just changed (and are still in the set of
-  // properties to transition), but for which we didn't just start the
-  // transition.  This can happen delay and duration are both zero, or
-  // because the new value is not interpolable.
-  // Note that we also do the latter set of work in
-  // nsTransitionManager::PruneCompletedTransitions.
-  if (collection) {
-    bool checkProperties =
-      disp->mTransitions[0].GetProperty() != eCSSPropertyExtra_all_properties;
-    nsCSSPropertySet allTransitionProperties;
-    if (checkProperties) {
-      for (uint32_t i = disp->mTransitionPropertyCount; i-- != 0; ) {
-        const StyleTransition& t = disp->mTransitions[i];
-        // FIXME: Would be good to find a way to share code between this
-        // interpretation of transition-property and the one above.
-        nsCSSProperty property = t.GetProperty();
-        if (property == eCSSPropertyExtra_no_properties ||
-            property == eCSSPropertyExtra_variable ||
-            property == eCSSProperty_UNKNOWN) {
-          // Nothing to do, but need to exclude this from cases below.
-        } else if (property == eCSSPropertyExtra_all_properties) {
-          for (nsCSSProperty p = nsCSSProperty(0);
-               p < eCSSProperty_COUNT_no_shorthands;
-               p = nsCSSProperty(p + 1)) {
-            allTransitionProperties.AddProperty(p);
-          }
-        } else if (nsCSSProps::IsShorthand(property)) {
-          CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(
-              subprop, property, nsCSSProps::eEnabledForAllContent) {
-            allTransitionProperties.AddProperty(*subprop);
-          }
-        } else {
-          allTransitionProperties.AddProperty(property);
-        }
-      }
-    }
-
-    OwningCSSTransitionPtrArray& animations = collection->mAnimations;
-    size_t i = animations.Length();
-    MOZ_ASSERT(i != 0, "empty transitions list?");
-    StyleAnimationValue currentValue;
-    do {
-      --i;
-      CSSTransition* anim = animations[i];
-      dom::KeyframeEffectReadOnly* effect = anim->GetEffect();
-      MOZ_ASSERT(effect && effect->Properties().Length() == 1,
-                 "Should have one animation property for a transition");
-      MOZ_ASSERT(effect && effect->Properties()[0].mSegments.Length() == 1,
-                 "Animation property should have one segment for a transition");
-      const AnimationProperty& prop = effect->Properties()[0];
-      const AnimationPropertySegment& segment = prop.mSegments[0];
-          // properties no longer in 'transition-property'
-      if ((checkProperties &&
-           !allTransitionProperties.HasProperty(prop.mProperty)) ||
-          // properties whose computed values changed but for which we
-          // did not start a new transition (because delay and
-          // duration are both zero, or because the new value is not
-          // interpolable); a new transition would have segment.mToValue
-          // matching currentValue
-          !ExtractComputedValueForTransition(prop.mProperty, afterChangeStyle,
-                                             currentValue) ||
-          currentValue != segment.mToValue) {
-        // stop the transition
-        if (anim->HasCurrentEffect()) {
-          EffectSet* effectSet = EffectSet::GetEffectSet(aElement, pseudoType);
-          if (effectSet) {
-            effectSet->UpdateAnimationGeneration(mPresContext);
-          }
-        }
-        anim->CancelFromStyle();
-        animations.RemoveElementAt(i);
-      }
-    } while (i != 0);
-
-    if (animations.IsEmpty()) {
-      collection->Destroy();
-      collection = nullptr;
-    }
   }
 
   MOZ_ASSERT(!startedAny || collection,
@@ -491,6 +371,145 @@ nsTransitionManager::StyleContextChanged(dom::Element *aElement,
   }
 }
 
+bool
+nsTransitionManager::UpdateTransitions(
+  const nsStyleDisplay* aDisp,
+  dom::Element* aElement,
+  CSSTransitionCollection*& aElementTransitions,
+  nsStyleContext* aOldStyleContext,
+  nsStyleContext* aNewStyleContext)
+{
+  MOZ_ASSERT(aDisp, "Null nsStyleDisplay");
+  MOZ_ASSERT(!aElementTransitions ||
+             aElementTransitions->mElement == aElement, "Element mismatch");
+
+  // Per http://lists.w3.org/Archives/Public/www-style/2009Aug/0109.html
+  // I'll consider only the transitions from the number of items in
+  // 'transition-property' on down, and later ones will override earlier
+  // ones (tracked using |whichStarted|).
+  bool startedAny = false;
+  nsCSSPropertySet whichStarted;
+  for (uint32_t i = aDisp->mTransitionPropertyCount; i-- != 0; ) {
+    const StyleTransition& t = aDisp->mTransitions[i];
+    // Check the combined duration (combination of delay and duration)
+    // first, since it defaults to zero, which means we can ignore the
+    // transition.
+    if (t.GetCombinedDuration() > 0.0f) {
+      // We might have something to transition.  See if any of the
+      // properties in question changed and are animatable.
+      // FIXME: Would be good to find a way to share code between this
+      // interpretation of transition-property and the one below.
+      nsCSSProperty property = t.GetProperty();
+      if (property == eCSSPropertyExtra_no_properties ||
+          property == eCSSPropertyExtra_variable ||
+          property == eCSSProperty_UNKNOWN) {
+        // Nothing to do, but need to exclude this from cases below.
+      } else if (property == eCSSPropertyExtra_all_properties) {
+        for (nsCSSProperty p = nsCSSProperty(0);
+             p < eCSSProperty_COUNT_no_shorthands;
+             p = nsCSSProperty(p + 1)) {
+          ConsiderStartingTransition(p, t, aElement, aElementTransitions,
+                                     aOldStyleContext, aNewStyleContext,
+                                     &startedAny, &whichStarted);
+        }
+      } else if (nsCSSProps::IsShorthand(property)) {
+        CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(subprop, property,
+                                             nsCSSProps::eEnabledForAllContent)
+        {
+          ConsiderStartingTransition(*subprop, t, aElement, aElementTransitions,
+                                     aOldStyleContext, aNewStyleContext,
+                                     &startedAny, &whichStarted);
+        }
+      } else {
+        ConsiderStartingTransition(property, t, aElement, aElementTransitions,
+                                   aOldStyleContext, aNewStyleContext,
+                                   &startedAny, &whichStarted);
+      }
+    }
+  }
+
+  // Stop any transitions for properties that are no longer in
+  // 'transition-property', including finished transitions.
+  // Also stop any transitions (and remove any finished transitions)
+  // for properties that just changed (and are still in the set of
+  // properties to transition), but for which we didn't just start the
+  // transition.  This can happen delay and duration are both zero, or
+  // because the new value is not interpolable.
+  // Note that we also do the latter set of work in
+  // nsTransitionManager::PruneCompletedTransitions.
+  if (aElementTransitions) {
+    bool checkProperties =
+      aDisp->mTransitions[0].GetProperty() != eCSSPropertyExtra_all_properties;
+    nsCSSPropertySet allTransitionProperties;
+    if (checkProperties) {
+      for (uint32_t i = aDisp->mTransitionPropertyCount; i-- != 0; ) {
+        const StyleTransition& t = aDisp->mTransitions[i];
+        // FIXME: Would be good to find a way to share code between this
+        // interpretation of transition-property and the one above.
+        nsCSSProperty property = t.GetProperty();
+        if (property == eCSSPropertyExtra_no_properties ||
+            property == eCSSPropertyExtra_variable ||
+            property == eCSSProperty_UNKNOWN) {
+          // Nothing to do, but need to exclude this from cases below.
+        } else if (property == eCSSPropertyExtra_all_properties) {
+          for (nsCSSProperty p = nsCSSProperty(0);
+               p < eCSSProperty_COUNT_no_shorthands;
+               p = nsCSSProperty(p + 1)) {
+            allTransitionProperties.AddProperty(p);
+          }
+        } else if (nsCSSProps::IsShorthand(property)) {
+          CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(
+              subprop, property, nsCSSProps::eEnabledForAllContent) {
+            allTransitionProperties.AddProperty(*subprop);
+          }
+        } else {
+          allTransitionProperties.AddProperty(property);
+        }
+      }
+    }
+
+    OwningCSSTransitionPtrArray& animations = aElementTransitions->mAnimations;
+    size_t i = animations.Length();
+    MOZ_ASSERT(i != 0, "empty transitions list?");
+    StyleAnimationValue currentValue;
+    do {
+      --i;
+      CSSTransition* anim = animations[i];
+          // properties no longer in 'transition-property'
+      if ((checkProperties &&
+           !allTransitionProperties.HasProperty(anim->TransitionProperty())) ||
+          // properties whose computed values changed but for which we
+          // did not start a new transition (because delay and
+          // duration are both zero, or because the new value is not
+          // interpolable); a new transition would have anim->ToValue()
+          // matching currentValue
+          !ExtractComputedValueForTransition(anim->TransitionProperty(),
+                                             aNewStyleContext,
+                                             currentValue) ||
+          currentValue != anim->ToValue()) {
+        // stop the transition
+        if (anim->HasCurrentEffect()) {
+          EffectSet* effectSet =
+            EffectSet::GetEffectSet(aElement,
+                                    aNewStyleContext->GetPseudoType());
+          if (effectSet) {
+            effectSet->UpdateAnimationGeneration(mPresContext);
+          }
+        }
+        anim->CancelFromStyle();
+        animations.RemoveElementAt(i);
+      }
+    } while (i != 0);
+
+    if (animations.IsEmpty()) {
+      aElementTransitions->Destroy();
+      aElementTransitions = nullptr;
+    }
+  }
+
+  return startedAny;
+}
+
 void
 nsTransitionManager::ConsiderStartingTransition(
   nsCSSProperty aProperty,
@@ -508,6 +527,13 @@ nsTransitionManager::ConsiderStartingTransition(
   NS_ASSERTION(!aElementTransitions ||
                aElementTransitions->mElement == aElement, "Element mismatch");
 
+  // Ignore disabled properties. We can arrive here if the transition-property
+  // is 'all' and the disabled property has a default value which derives value
+  // from another property, e.g. color.
+  if (!nsCSSProps::IsEnabled(aProperty, nsCSSProps::eEnabledForAllContent)) {
+    return;
+  }
+
   if (aWhichStarted->HasProperty(aProperty)) {
     // A later item in transition-property already started a
     // transition for this property, so we ignore this one.
@@ -667,19 +693,9 @@ nsTransitionManager::ConsiderStartingTransition(
                                   aNewStyleContext->GetPseudoType(), timing,
                                   startForReversingTest, reversePortion);
 
-  AnimationProperty& prop = *pt->Properties().AppendElement();
+  pt->SetFrames(GetTransitionKeyframes(aNewStyleContext, aProperty,
-  prop.mProperty = aProperty;
+                                       Move(startValue), Move(endValue), tf),
-
+                aNewStyleContext);
-  AnimationPropertySegment& segment = *prop.mSegments.AppendElement();
-  segment.mFromValue = startValue;
-  segment.mToValue = endValue;
-  segment.mFromKey = 0;
-  segment.mToKey = 1;
-  if (tf.mType != nsTimingFunction::Type::Linear) {
-    ComputedTimingFunction computedTimingFunction;
-    computedTimingFunction.Init(tf);
-    segment.mTimingFunction = Some(computedTimingFunction);
-  }
 
   MOZ_ASSERT(mPresContext->RestyleManager()->IsGecko(),
              "ServoRestyleManager should not use nsTransitionManager "
@@ -747,6 +763,43 @@ nsTransitionManager::ConsiderStartingTransition(
   aWhichStarted->AddProperty(aProperty);
 }
 
+static Keyframe&
+AppendKeyframe(double aOffset, nsCSSProperty aProperty,
+               StyleAnimationValue&& aValue, nsTArray<Keyframe>& aKeyframes)
+{
+  Keyframe& frame = *aKeyframes.AppendElement();
+  frame.mOffset.emplace(aOffset);
+  PropertyValuePair& pv = *frame.mPropertyValues.AppendElement();
+  pv.mProperty = aProperty;
+  DebugOnly<bool> uncomputeResult =
+    StyleAnimationValue::UncomputeValue(aProperty, Move(aValue), pv.mValue);
+  MOZ_ASSERT(uncomputeResult,
+              "Unable to get specified value from computed value");
+  return frame;
+}
+
+nsTArray<Keyframe>
+nsTransitionManager::GetTransitionKeyframes(
+    nsStyleContext* aStyleContext,
+    nsCSSProperty aProperty,
+    StyleAnimationValue&& aStartValue,
+    StyleAnimationValue&& aEndValue,
+    const nsTimingFunction& aTimingFunction)
+{
+  nsTArray<Keyframe> keyframes(2);
+
+  Keyframe& fromFrame = AppendKeyframe(0.0, aProperty, Move(aStartValue),
+                                       keyframes);
+  if (aTimingFunction.mType != nsTimingFunction::Type::Linear) {
+    fromFrame.mTimingFunction.emplace();
+    fromFrame.mTimingFunction->Init(aTimingFunction);
+  }
+
+  AppendKeyframe(1.0, aProperty, Move(aEndValue), keyframes);
+
+  return keyframes;
+}
+
 void
 nsTransitionManager::PruneCompletedTransitions(mozilla::dom::Element* aElement,
                                                CSSPseudoElementType aPseudoType,
@@ -775,20 +828,13 @@ nsTransitionManager::PruneCompletedTransitions(mozilla::dom::Element* aElement,
       continue;
     }
 
-    dom::KeyframeEffectReadOnly* effect = anim->GetEffect();
-    MOZ_ASSERT(effect->Properties().Length() == 1,
-               "Should have one animation property for a transition");
-    MOZ_ASSERT(effect->Properties()[0].mSegments.Length() == 1,
-               "Animation property should have one segment for a transition");
-    const AnimationProperty& prop = effect->Properties()[0];
-    const AnimationPropertySegment& segment = prop.mSegments[0];
-
     // Since effect is a finished transition, we know it didn't
     // influence style.
     StyleAnimationValue currentValue;
-    if (!ExtractComputedValueForTransition(prop.mProperty, aNewStyleContext,
+    if (!ExtractComputedValueForTransition(anim->TransitionProperty(),
+                                           aNewStyleContext,
                                            currentValue) ||
-        currentValue != segment.mToValue) {
+        currentValue != anim->ToValue()) {
       anim->CancelFromStyle();
       animations.RemoveElementAt(i);
     }

layout/style/nsTransitionManager.h

@@ -23,6 +23,7 @@ class nsCSSPropertySet;
 
 namespace mozilla {
 enum class CSSPseudoElementType : uint8_t;
+struct Keyframe;
 struct StyleTransition;
 } // namespace mozilla
 
@@ -52,19 +53,28 @@ struct ElementPropertyTransition : public dom::KeyframeEffectReadOnly
   }
 
   nsCSSProperty TransitionProperty() const {
-    MOZ_ASSERT(mProperties.Length() == 1,
+    MOZ_ASSERT(mFrames.Length() == 2,
-               "Transitions should have exactly one animation property. "
+               "Transitions should have exactly two animation frames. "
                "Perhaps we are using an un-initialized transition?");
-    return mProperties[0].mProperty;
+    MOZ_ASSERT(mFrames[0].mPropertyValues.Length() == 1,
+               "Transitions should have exactly one property in their first "
+               "frame");
+    return mFrames[0].mPropertyValues[0].mProperty;
   }
 
   StyleAnimationValue ToValue() const {
-    MOZ_ASSERT(mProperties.Length() == 1,
+    // If we failed to generate properties from the transition frames,
-               "Transitions should have exactly one animation property");
+    // return a null value but also show a warning since we should be
-    MOZ_ASSERT(mProperties[0].mSegments.Length() == 1,
+    // detecting that kind of situation in advance and not generating a
-               "Transitions should have one animation property segment ");
+    // transition in the first place.
+    if (mProperties.Length() < 1 ||
+        mProperties[0].mSegments.Length() < 1) {
+      NS_WARNING("Failed to generate transition property values");
+      return StyleAnimationValue();
+    }
     return mProperties[0].mSegments[0].mToValue;
   }
+
   // This is the start value to be used for a check for whether a
   // transition is being reversed.  Normally the same as
   // mProperties[0].mSegments[0].mFromValue, except when this transition
@@ -147,6 +157,7 @@ public:
   void Tick() override;
 
   nsCSSProperty TransitionProperty() const;
+  StyleAnimationValue ToValue() const;
 
   bool HasLowerCompositeOrderThan(const CSSTransition& aOther) const;
   EffectCompositor::CascadeLevel CascadeLevel() const override
@@ -250,10 +261,10 @@ struct TransitionEventInfo {
     , mTimeStamp(aTimeStamp)
   {
     // XXX Looks like nobody initialize WidgetEvent::time
-    mEvent.propertyName =
+    mEvent.mPropertyName =
       NS_ConvertUTF8toUTF16(nsCSSProps::GetStringValue(aProperty));
-    mEvent.elapsedTime = aDuration.ToSeconds();
+    mEvent.mElapsedTime = aDuration.ToSeconds();
-    mEvent.pseudoElement =
+    mEvent.mPseudoElement =
       AnimationCollection<dom::CSSTransition>::PseudoTypeAsString(aPseudoType);
   }
 
@@ -351,6 +362,17 @@ protected:
   typedef nsTArray<RefPtr<mozilla::dom::CSSTransition>>
     OwningCSSTransitionPtrArray;
 
+  // Update the transitions. It'd start new, replace, or stop current
+  // transitions if need. aDisp and aElement shouldn't be nullptr.
+  // aElementTransitions is the collection of current transitions, and it
+  // could be a nullptr if we don't have any transitions.
+  bool
+  UpdateTransitions(const nsStyleDisplay* aDisp,
+                    mozilla::dom::Element* aElement,
+                    CSSTransitionCollection*& aElementTransitions,
+                    nsStyleContext* aOldStyleContext,
+                    nsStyleContext* aNewStyleContext);
+
   void
   ConsiderStartingTransition(nsCSSProperty aProperty,
                              const mozilla::StyleTransition& aTransition,
@@ -361,6 +383,13 @@ protected:
                              bool* aStartedAny,
                              nsCSSPropertySet* aWhichStarted);
 
+  nsTArray<mozilla::Keyframe> GetTransitionKeyframes(
+    nsStyleContext* aStyleContext,
+    nsCSSProperty aProperty,
+    mozilla::StyleAnimationValue&& aStartValue,
+    mozilla::StyleAnimationValue&& aEndValue,
+    const nsTimingFunction& aTimingFunction);
+
   bool mInAnimationOnlyStyleUpdate;
 
   mozilla::DelayedEventDispatcher<mozilla::TransitionEventInfo>

layout/style/test/mochitest.ini

@@ -264,6 +264,8 @@ skip-if = (android_version == '18' && debug) # bug 1159532
 [test_transitions_per_property.html]
 skip-if = buildapp == 'b2g' || toolkit == 'android' #bug 775227 # b2g(times out, needs more time + various failures) b2g-debug(times out, needs more time + various failures) b2g-desktop(times out, needs more time + various failures)
 [test_transitions_step_functions.html]
+[test_transitions_with_displaynone.html]
+[test_transitions_with_disabled_properties.html]
 [test_unclosed_parentheses.html]
 [test_unicode_range_loading.html]
 support-files = ../../reftests/fonts/markA.woff ../../reftests/fonts/markB.woff ../../reftests/fonts/markC.woff ../../reftests/fonts/markD.woff
@@ -298,6 +300,5 @@ skip-if = buildapp == 'b2g' || toolkit == 'android' #TIMED_OUT # b2g(bug 870262,
 skip-if = buildapp == 'b2g' || toolkit == 'android' #TIMED_OUT # b2g(bug 870262, :visited support) b2g-debug(bug 870262, :visited support) b2g-desktop(bug 870262, :visited support)
 [test_visited_reftests.html]
 skip-if = buildapp == 'b2g' || toolkit == 'android' #TIMED_OUT # b2g(bug 870262, :visited support) b2g-debug(bug 870262, :visited support) b2g-desktop(bug 870262, :visited support)
-[test_webkit_box_orient.html]
 [test_webkit_device_pixel_ratio.html]
 [test_asyncopen2.html]

layout/style/test/property_database.js

@@ -665,7 +665,7 @@ if (IsCSSPropertyPrefEnabled("layout.css.prefixes.webkit")) {
     "-webkit-gradient(linear, 1 2, 3 4, color-stop(0, rgb(1,2,3)))",
     "-webkit-gradient(linear, 1 2, 3 4, color-stop(0, #00ff00))",
     "-webkit-gradient(linear, 1 2, 3 4, color-stop(0, #00f))",
-    "-webkit-gradient(linear, 1 2, 3 4, color-stop(0, hsla(240, 30%, 50%, 0.9)))",
+    "-webkit-gradient(linear, 1 2, 3 4, color-stop(0, hsla(240, 30%, 50%, 0.8)))",
     "-webkit-gradient(linear, 1 2, 3 4, color-stop(0, rgba(255, 230, 10, 0.5)))",
 
     // linear w/ multiple color stops:
@@ -4331,7 +4331,7 @@ var gCSSProperties = {
     initial_values: [ "auto", "normal" ],
     other_values: [ "start", "end", "flex-start", "flex-end", "self-start",
                     "self-end", "center", "left", "right", "baseline",
-                    "last-baseline", "stretch", "left true", "true right",
+                    "last-baseline", "stretch", "left unsafe", "unsafe right",
                     "safe right", "center safe" ],
     invalid_values: [ "space-between", "abc", "30px", "none",
                       "legacy left", "right legacy" ]
@@ -4875,25 +4875,6 @@ function logical_box_prop_get_computed(cs, property)
   return cs.getPropertyValue(property);
 }
 
-// Helper to get computed style of "-webkit-box-orient" from "flex-direction"
-// and the "writing-mode".
-function webkit_orient_get_computed(cs, property)
-{
-  var writingMode = cs.getPropertyValue("writing-mode") || "horizontal-tb";
-
-  var mapping; // map from flex-direction values to -webkit-box-orient values.
-  if (writingMode == "horizontal-tb") {
-    // Horizontal writing-mode
-    mapping = { "row" : "horizontal", "column" : "vertical"};
-  } else {
-    // Vertical writing-mode
-    mapping = { "row" : "vertical",   "column" : "horizontal"};
-  }
-
-  var flexDirection = cs.getPropertyValue("flex-direction");
-  return mapping[flexDirection];
-}
-
 // Get the computed value for a property.  For shorthands, return the
 // computed values of all the subproperties, delimited by " ; ".
 function get_computed_value(cs, property)
@@ -6590,17 +6571,6 @@ if (IsCSSPropertyPrefEnabled("layout.css.background-blend-mode.enabled")) {
   };
 }
 
-if (SpecialPowers.getBoolPref("layout.css.will-change.enabled")) {
-  gCSSProperties["will-change"] = {
-    domProp: "willChange",
-    inherited: false,
-    type: CSS_TYPE_LONGHAND,
-    initial_values: [ "auto" ],
-    other_values: [ "scroll-position", "contents", "transform", "opacity", "scroll-position, transform", "transform, opacity", "contents, transform", "property-that-doesnt-exist-yet" ],
-    invalid_values: [ "none", "all", "default", "auto, scroll-position", "scroll-position, auto", "transform scroll-position", ",", "trailing,", "will-change", "transform, will-change" ]
-  };
-}
-
 if (IsCSSPropertyPrefEnabled("layout.css.object-fit-and-position.enabled")) {
   gCSSProperties["object-fit"] = {
     domProp: "objectFit",
@@ -7216,13 +7186,6 @@ if (IsCSSPropertyPrefEnabled("layout.css.prefixes.webkit")) {
     alias_for: "border-bottom-right-radius",
     subproperties: [ "border-bottom-right-radius" ],
   };
-  gCSSProperties["-webkit-appearance"] = {
-    domProp: "webkitAppearance",
-    inherited: false,
-    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
-    alias_for: "-moz-appearance",
-    subproperties: [ "-moz-appearance" ],
-  };
   gCSSProperties["-webkit-background-clip"] = {
     domProp: "webkitBackgroundClip",
     inherited: false,
@@ -7269,44 +7232,43 @@ if (IsCSSPropertyPrefEnabled("layout.css.prefixes.webkit")) {
     domProp: "webkitBoxFlex",
     inherited: false,
     type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
-    alias_for: "flex-grow",
+    alias_for: "-moz-box-flex",
-    subproperties: [ "flex-grow" ],
+    subproperties: [ "-moz-box-flex" ],
   };
   gCSSProperties["-webkit-box-ordinal-group"] = {
     domProp: "webkitBoxOrdinalGroup",
     inherited: false,
     type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
-    alias_for: "order",
+    alias_for: "-moz-box-ordinal-group",
-    subproperties: [ "order" ],
+    subproperties: [ "-moz-box-ordinal-group" ],
   };
-  /* This one is not an alias - it's implemented as a logical property: */
   gCSSProperties["-webkit-box-orient"] = {
     domProp: "webkitBoxOrient",
     inherited: false,
-    type: CSS_TYPE_LONGHAND,
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
-    logical: true,
+    alias_for: "-moz-box-orient",
-    get_computed: webkit_orient_get_computed,
+    subproperties: [ "-moz-box-orient" ],
-    initial_values: [ "horizontal" ],
+  };
-    other_values: [ "vertical" ],
+  gCSSProperties["-webkit-box-direction"] = {
-    invalid_values: [
+    domProp: "webkitBoxDirection",
-      "0", "0px", "auto",
+    inherited: false,
-      /* Flex-direction values: */
+    type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
-      "row", "column", "row-reverse", "column-reverse",
+    alias_for: "-moz-box-direction",
-    ],
+    subproperties: [ "-moz-box-direction" ],
   };
   gCSSProperties["-webkit-box-align"] = {
     domProp: "webkitBoxAlign",
     inherited: false,
     type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
-    alias_for: "align-items",
+    alias_for: "-moz-box-align",
-    subproperties: [ "align-items" ],
+    subproperties: [ "-moz-box-align" ],
   };
   gCSSProperties["-webkit-box-pack"] = {
     domProp: "webkitBoxPack",
     inherited: false,
     type: CSS_TYPE_SHORTHAND_AND_LONGHAND,
-    alias_for: "justify-content",
+    alias_for: "-moz-box-pack",
-    subproperties: [ "justify-content" ],
+    subproperties: [ "-moz-box-pack" ],
   };
   gCSSProperties["-webkit-user-select"] = {
     domProp: "webkitUserSelect",

layout/style/test/test_transitions.html

@@ -738,18 +738,15 @@ add_future_call(8, check_number_tests);
 
 function check_display_tests(time)
 {
-    var tf = timingFunctions["ease-in-out"];
     for (var i in display_tests) {
         var p = display_tests[i];
 
-        check_transition_value(tf, 0, 8, 0, 100,
+        // There is no transition if the old or new style is display:none, so
-                               getComputedStyle(p, "").textIndent,
+        // the computed value is always the end value.
-                               "display test for test with " +
+        var computedValue = getComputedStyle(p, "").textIndent;
-                                 p.childNodes[0].data,
+        is(computedValue, "100px",
-        // TODO: Making transitions work on 'display:none' elements is
+           "display test for test with " + p.childNodes[0].data +
-        // still not implemented.
+           ": computed value " + computedValue + " should be 100px.");
-                               function(range) { return p != to_none_test &&
-                                                 range[1] < 100 });
     }
 }
 

layout/style/test/test_transitions_with_disabled_properties.html

@@ -0,0 +1,56 @@
+<!doctype html>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1265611
+-->
+<head>
+  <meta charset=utf-8>
+  <title>Test for bug 1265611</title>
+  <script type="application/javascript"
+    src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+  <style>
+  #display {
+    transition: all 0.01s;
+  }
+  </style>
+</head>
+<body>
+<a target="_blank"
+  href="https://bugzilla.mozilla.org/show_bug.cgi?id=1265611">Mozilla Bug
+  1265611</a>
+
+<div id="display"></div>
+<pre id="test">
+<script>
+SimpleTest.waitForExplicitFinish();
+
+/*
+ * This tests for transitions generated on the -webkit-text-fill-color property.
+ * This property has an initial value of 'currentcolor' so by triggering a
+ * transition on the 'color' property we also--at least at the point when
+ * this test was written--trigger a transition on the -webkit-text-fill-color
+ * property (that behavior may change in bug 1260543).
+ *
+ * However, before beginning the test we disable -webkit-text-fill-color by
+ * setting layout.css.prefixes.webkit to false. This code tests that we don't
+ * end up triggering a transition on the (disabled) property in that case.
+ */
+SpecialPowers.pushPrefEnv({'set': [['layout.css.prefixes.webkit', false],
+                                   ['dom.animations-api.core.enabled', true]] },
+  () => {
+    var display = document.getElementById('display');
+    display.style.color = 'green';
+
+    var transitionedProperties =
+      display.getAnimations().map(transition => transition.transitionProperty);
+
+    ok(!transitionedProperties.includes('-webkit-text-fill-color'),
+       'We should not fire transitions for properties disabled by prefs');
+    SimpleTest.finish();
+  }
+);
+</script>
+</pre>
+</body>
+</html>

layout/style/test/test_transitions_with_displaynone.html

@@ -0,0 +1,71 @@
+<!doctype html>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1182856
+-->
+<head>
+  <title>Test for Bug 1182856</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="application/javascript" src="animation_utils.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+  <style>
+  #display {
+    background: blue;
+    height: 10px;
+    width: 10px;
+  }
+  </style>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1182856">Mozilla Bug 1182856</a>
+
+<div id="display"></div>
+<pre id="test"></pre>
+
+<script type="application/javascript">
+'use strict';
+
+function TestDisplayNoneTurnOffTransitions(elem, cs, elemToDisplayNone, name) {
+  var ended = false;
+  var markEnded = function () {
+    ended = true;
+  };
+  elem.addEventListener('transitionend', markEnded, false);
+
+  cs.marginLeft; // flush
+  elem.style.marginLeft = "100px"; // start transition
+  is(cs.marginLeft, "0px", name + ": margin-left at 0s");
+
+  advance_clock(1000);
+  is(cs.marginLeft, "10px", name + ": margin-left at 1s");
+
+  elemToDisplayNone.style.display = "none";
+  is(cs.marginLeft, "100px", name + ": margin-left after display:none");
+
+  advance_clock(10000);
+  ok(!ended, name + ": Should not get transitionend");
+}
+
+advance_clock(0);
+
+// Set display:none on the target.
+var [div, cs] = new_div("margin-left: 0px; transition: margin-left 10s linear");
+TestDisplayNoneTurnOffTransitions(div, cs, div, "Set display:none on target");
+done_div();
+
+// Set display:none on the ancestor of the target.
+var [div, cs] = new_div("margin-left: 0px; transition: margin-left 10s linear");
+var ancestor = document.createElement("div");
+div.parentNode.insertBefore(ancestor, div);
+ancestor.appendChild(div);
+TestDisplayNoneTurnOffTransitions(div, cs, ancestor,
+                                  "Set display:none on ancestor");
+ancestor.parentNode.insertBefore(div, ancestor);
+ancestor.remove();
+done_div();
+
+SpecialPowers.DOMWindowUtils.restoreNormalRefresh();
+
+</script>
+</body>
+</html>