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

- Bug 1196462 - Add a pref to highlight checkerboarded areas for debugging. r=kats (ffd1d24515)
- Bug 1207944 (part 1) - Pass a gfx::Color& instead of a gfxRGBA& to SetDeviceColor(). r=jwatt. (117317c610)
- Bug 1207944 (part 2) - Pass a gfx::Color& instead of a gfxRGBA& to GetDeviceColor(). r=jwatt. (82739fb35a)
- Bug 1207944 (part 3) - Add a gfxContext::SetColor method that takes a gfx::Color&. r=jwatt. (65d081203d)
- Bug 1207944 (part 4) - Use SetColor(const Color&) when setting from an nscolor. r=jwatt. (4e3ca8e36b)
- Bug 1207944 (part 5) - Use SetColor(const Color&) when setting from a constructed gfxRGBA. r=jwatt. (d4583dbee1)
- Bug 1207944 (part 6) - Use gfx::Color instead of gfxRGBA in ColorStop. r=jwatt. (74ad3407a2)
- Bug 1207944 (part 7) - Use gfx::Color instead of gfxRGBA in BlurCache. r=jwatt. (1402a3f334)
- Bug 1207944 (part 8) - Change nsDisplayBackgroundColor::mColor from gfxRGBA to gfx::Color. r=jwatt. (42259ef66b)
- Bug 1207944 (part 9) - Remove SetColor(const gfxRGBA&). r=jwatt. (064879c237)
- Bug 1208283 (part 1) - Change gfxPattern's single-arg constructor to take a gfx::Color& instead of a gfxRGBA&. r=jwatt. (1aa348d966)
- Bug 1208283 (part 2) - Change ColorLayer::mColor, ColorLayerProperties::mColor, ReadbackLayer::mBackgroundColor from gfxRBGA to gfx::Color. r=jwatt. (859d5c4a45)
- Bug 1208283 (part 3) - Remove the ToDeviceColor() that takes a gfxRGBA. r=jwatt. (525cd78338)
- Bug 1208283 (part 4) - Change FrameMetrics::mBackgroundColor from gfxRGBA to gfx::Color. r=jwatt. (49e3c39013)
- Bug 1208283 (part 5) - Pass a gfx::Color instead of a gfxRGBA to PaintRectToSurface(). r=jwatt. (04997ce877)
- Bug 1157669 - Assert aGroupTarget is not null in PaintSelfOrChildren method. r=nical (7f3cc9c792)
- Bug 1208300 (part 4) - Remove gfxRGBA and some related things. r=jwatt. (c158d04b63)
- Bug 1207931 - Remove no-longer-needed SetBackgroundColor IPC message. r=mattwoodrow. (a54d91bf53)
- Bug 1206904 - Work around APZ crashes when dealing with nested content processes. r=botond (3252333fb4)
- Bug 1189611 - Improve the APZ minimap position and ignore trivial APZ. r=kats (12c5ff5215)
- Bug 1196412 - Correctly scale canvas layers that have a transform applied to fill the screen, r=vlad (5036fd706c)
- Bug 1189473 - Don't paint the tiles in the APZ minimap. r=mstange (fc3db414f7)
- Bug 1189924 - Add a background color to the APZ minimap. r=kats (dd347db883)
- add some dead stuff back in (de8fe1d1a0)
- Treat mix-blend-mode layers as transparent for occlusion culling. (bug 1207041, r=mstange) (c3c3844d7b)

layout/base/nsPresShell.cpp

@@ -4638,7 +4638,7 @@ PresShell::RenderDocument(const nsRect& aRect, uint32_t aFlags,
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
   if (!rootFrame) {
     // Nothing to paint, just fill the rect
-    aThebesContext->SetColor(gfxRGBA(aBackgroundColor));
+    aThebesContext->SetColor(Color::FromABGR(aBackgroundColor));
     aThebesContext->Fill();
     return NS_OK;
   }
@@ -5312,11 +5312,6 @@ void PresShell::UpdateCanvasBackground()
   if (!FrameConstructor()->GetRootElementFrame()) {
     mCanvasBackgroundColor = GetDefaultBackgroundColorToDraw();
   }
-  if (XRE_IsContentProcess() && mPresContext->IsRoot()) {
-    if (TabChild* tabChild = TabChild::GetFrom(this)) {
-      tabChild->SetBackgroundColor(mCanvasBackgroundColor);
-    }
-  }
 }
 
 nscolor PresShell::ComputeBackstopColor(nsView* aDisplayRoot)
@@ -6175,7 +6170,7 @@ PresShell::Paint(nsView*        aViewToPaint,
     nsIntRect bounds =
       pc->GetVisibleArea().ToOutsidePixels(pc->AppUnitsPerDevPixel());
     bgcolor = NS_ComposeColors(bgcolor, mCanvasBackgroundColor);
-    root->SetColor(bgcolor);
+    root->SetColor(Color::FromABGR(bgcolor));
     root->SetVisibleRegion(bounds);
     layerManager->SetRoot(root);
   }
@@ -10240,23 +10235,23 @@ void ReflowCountMgr::PaintCount(const char*     aName,
       fm->SetTextRunRTL(false);
       width = fm->GetWidth(buf, len, aRenderingContext);;
 
-      uint32_t color;
-      uint32_t color2;
+      Color color;
+      Color color2;
       if (aColor != 0) {
-        color  = aColor;
-        color2 = NS_RGB(0,0,0);
+        color  = Color::FromABGR(aColor);
+        color2 = Color(0.f, 0.f, 0.f);
       } else {
-        uint8_t rc = 0, gc = 0, bc = 0;
+        gfx::Float rc = 0.f, gc = 0.f, bc = 0.f;
         if (counter->mCount < 5) {
-          rc = 255;
-          gc = 255;
-        } else if ( counter->mCount < 11) {
-          gc = 255;
+          rc = 1.f;
+          gc = 1.f;
+        } else if (counter->mCount < 11) {
+          gc = 1.f;
         } else {
-          rc = 255;
+          rc = 1.f;
         }
-        color  = NS_RGB(rc,gc,bc);
-        color2 = NS_RGB(rc/2,gc/2,bc/2);
+        color  = Color(rc, gc, bc);
+        color2 = Color(rc/2, gc/2, bc/2);
       }
 
       nsRect rect(0,0, width+15, height+15);