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

- Bug 1191491 - Do not dispatch an audio-playback notification when swapping browsers; r=smaug (dacb2ff694)
- Bug 1192252 - Add a helper RAII class for managing the cleanup in nsFrameLoader::SwapWithOtherLoader; r=smaug (362488db65)

docshell/base/nsDocShell.cpp

@@ -782,6 +782,7 @@ nsDocShell::nsDocShell()
   , mUseRemoteTabs(false)
   , mDeviceSizeIsPageSize(false)
   , mWindowDraggingAllowed(false)
+  , mInFrameSwap(false)
   , mCanExecuteScripts(false)
   , mFiredUnloadEvent(false)
   , mEODForCurrentDocument(false)
@@ -14243,3 +14244,16 @@ nsDocShell::GetPaymentRequestId(nsAString& aPaymentRequestId)
   aPaymentRequestId = GetInheritedPaymentRequestId();
   return NS_OK;
 }
+
+bool
+nsDocShell::InFrameSwap()
+{
+  nsRefPtr<nsDocShell> shell = this;
+  do {
+    if (shell->mInFrameSwap) {
+      return true;
+    }
+    shell = shell->GetParentDocshell();
+  } while (shell);
+  return false;
+}

docshell/base/nsDocShell.h

@@ -262,6 +262,12 @@ public:
   // is no longer applied
   void NotifyAsyncPanZoomStopped();
 
+  void SetInFrameSwap(bool aInSwap)
+  {
+    mInFrameSwap = aInSwap;
+  }
+  bool InFrameSwap();
+
 private:
   // An observed docshell wrapper is created when recording markers is enabled.
   mozilla::UniquePtr<mozilla::ObservedDocShell> mObserved;
@@ -910,6 +916,7 @@ protected:
   bool mUseRemoteTabs;
   bool mDeviceSizeIsPageSize;
   bool mWindowDraggingAllowed;
+  bool mInFrameSwap;
 
   // Because scriptability depends on the mAllowJavascript values of our
   // ancestors, we cache the effective scriptability and recompute it when

dom/base/nsFrameLoader.cpp

@@ -939,6 +939,60 @@ nsFrameLoader::SwapWithOtherRemoteLoader(nsFrameLoader* aOther,
   return NS_OK;
 }
 
+class MOZ_STACK_CLASS AutoResetInFrameSwap final
+{
+public:
+  AutoResetInFrameSwap(nsFrameLoader* aThisFrameLoader,
+                       nsFrameLoader* aOtherFrameLoader,
+                       nsDocShell* aThisDocShell,
+                       nsDocShell* aOtherDocShell,
+                       EventTarget* aThisEventTarget,
+                       EventTarget* aOtherEventTarget
+                       MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
+    : mThisFrameLoader(aThisFrameLoader)
+    , mOtherFrameLoader(aOtherFrameLoader)
+    , mThisDocShell(aThisDocShell)
+    , mOtherDocShell(aOtherDocShell)
+    , mThisEventTarget(aThisEventTarget)
+    , mOtherEventTarget(aOtherEventTarget)
+  {
+    MOZ_GUARD_OBJECT_NOTIFIER_INIT;
+
+    mThisFrameLoader->mInSwap = true;
+    mOtherFrameLoader->mInSwap = true;
+    mThisDocShell->SetInFrameSwap(true);
+    mOtherDocShell->SetInFrameSwap(true);
+
+    // Fire pageshow events on still-loading pages, and then fire pagehide
+    // events.  Note that we do NOT fire these in the normal way, but just fire
+    // them on the chrome event handlers.
+    nsContentUtils::FirePageShowEvent(mThisDocShell, mThisEventTarget, false);
+    nsContentUtils::FirePageShowEvent(mOtherDocShell, mOtherEventTarget, false);
+    nsContentUtils::FirePageHideEvent(mThisDocShell, mThisEventTarget);
+    nsContentUtils::FirePageHideEvent(mOtherDocShell, mOtherEventTarget);
+  }
+
+  ~AutoResetInFrameSwap()
+  {
+    nsContentUtils::FirePageShowEvent(mThisDocShell, mThisEventTarget, true);
+    nsContentUtils::FirePageShowEvent(mOtherDocShell, mOtherEventTarget, true);
+
+    mThisFrameLoader->mInSwap = false;
+    mOtherFrameLoader->mInSwap = false;
+    mThisDocShell->SetInFrameSwap(false);
+    mOtherDocShell->SetInFrameSwap(false);
+  }
+
+private:
+  nsRefPtr<nsFrameLoader> mThisFrameLoader;
+  nsRefPtr<nsFrameLoader> mOtherFrameLoader;
+  nsRefPtr<nsDocShell> mThisDocShell;
+  nsRefPtr<nsDocShell> mOtherDocShell;
+  nsCOMPtr<EventTarget> mThisEventTarget;
+  nsCOMPtr<EventTarget> mOtherEventTarget;
+  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
+};
+
 nsresult
 nsFrameLoader::SwapWithOtherLoader(nsFrameLoader* aOther,
                                    nsRefPtr<nsFrameLoader>& aFirstToSwap,
@@ -975,8 +1029,8 @@ nsFrameLoader::SwapWithOtherLoader(nsFrameLoader* aOther,
     return NS_ERROR_DOM_SECURITY_ERR;
   }
 
-  nsCOMPtr<nsIDocShell> ourDocshell = GetExistingDocShell();
-  nsCOMPtr<nsIDocShell> otherDocshell = aOther->GetExistingDocShell();
+  nsRefPtr<nsDocShell> ourDocshell = static_cast<nsDocShell*>(GetExistingDocShell());
+  nsRefPtr<nsDocShell> otherDocshell = static_cast<nsDocShell*>(aOther->GetExistingDocShell());
   if (!ourDocshell || !otherDocshell) {
     // How odd
     return NS_ERROR_NOT_IMPLEMENTED;
@@ -1107,39 +1161,23 @@ nsFrameLoader::SwapWithOtherLoader(nsFrameLoader* aOther,
   if (mInSwap || aOther->mInSwap) {
     return NS_ERROR_NOT_IMPLEMENTED;
   }
-  mInSwap = aOther->mInSwap = true;
+  AutoResetInFrameSwap autoFrameSwap(this, aOther, ourDocshell, otherDocshell,
+                                     ourEventTarget, otherEventTarget);
 
-  // Fire pageshow events on still-loading pages, and then fire pagehide
-  // events.  Note that we do NOT fire these in the normal way, but just fire
-  // them on the chrome event handlers.
-  nsContentUtils::FirePageShowEvent(ourDocshell, ourEventTarget, false);
-  nsContentUtils::FirePageShowEvent(otherDocshell, otherEventTarget, false);
-  nsContentUtils::FirePageHideEvent(ourDocshell, ourEventTarget);
-  nsContentUtils::FirePageHideEvent(otherDocshell, otherEventTarget);
-  
   nsIFrame* ourFrame = ourContent->GetPrimaryFrame();
   nsIFrame* otherFrame = otherContent->GetPrimaryFrame();
   if (!ourFrame || !otherFrame) {
-    mInSwap = aOther->mInSwap = false;
-    nsContentUtils::FirePageShowEvent(ourDocshell, ourEventTarget, true);
-    nsContentUtils::FirePageShowEvent(otherDocshell, otherEventTarget, true);
     return NS_ERROR_NOT_IMPLEMENTED;
   }
 
   nsSubDocumentFrame* ourFrameFrame = do_QueryFrame(ourFrame);
   if (!ourFrameFrame) {
-    mInSwap = aOther->mInSwap = false;
-    nsContentUtils::FirePageShowEvent(ourDocshell, ourEventTarget, true);
-    nsContentUtils::FirePageShowEvent(otherDocshell, otherEventTarget, true);
     return NS_ERROR_NOT_IMPLEMENTED;
   }
 
   // OK.  First begin to swap the docshells in the two nsIFrames
   rv = ourFrameFrame->BeginSwapDocShells(otherFrame);
   if (NS_FAILED(rv)) {
-    mInSwap = aOther->mInSwap = false;
-    nsContentUtils::FirePageShowEvent(ourDocshell, ourEventTarget, true);
-    nsContentUtils::FirePageShowEvent(otherDocshell, otherEventTarget, true);
     return rv;
   }
 
@@ -1242,10 +1280,6 @@ nsFrameLoader::SwapWithOtherLoader(nsFrameLoader* aOther,
   ourParentDocument->FlushPendingNotifications(Flush_Layout);
   otherParentDocument->FlushPendingNotifications(Flush_Layout);
 
-  nsContentUtils::FirePageShowEvent(ourDocshell, ourEventTarget, true);
-  nsContentUtils::FirePageShowEvent(otherDocshell, otherEventTarget, true);
-
-  mInSwap = aOther->mInSwap = false;
   return NS_OK;
 }
 

dom/base/nsFrameLoader.h

@@ -31,6 +31,7 @@ class nsSubDocumentFrame;
 class nsView;
 class nsIInProcessContentFrameMessageManager;
 class AutoResetInShow;
+class AutoResetInFrameSwap;
 class nsITabParent;
 class nsIDocShellTreeItem;
 class nsIDocShellTreeOwner;
@@ -58,6 +59,7 @@ class nsFrameLoader final : public nsIFrameLoader,
                             public mozilla::dom::ipc::MessageManagerCallback
 {
   friend class AutoResetInShow;
+  friend class AutoResetInFrameSwap;
   typedef mozilla::dom::PBrowserParent PBrowserParent;
   typedef mozilla::dom::TabParent TabParent;
   typedef mozilla::layout::RenderFrameParent RenderFrameParent;

dom/html/HTMLMediaElement.cpp

@@ -102,6 +102,7 @@ static PRLogModuleInfo* gMediaElementEventsLog;
 
 #include "nsIPermissionManager.h"
 #include "nsContentTypeParser.h"
+#include "nsDocShell.h"
 
 #include "mozilla/EventStateManager.h"
 
@@ -4016,7 +4017,14 @@ void HTMLMediaElement::NotifyOwnerDocumentActivityChanged()
   if (pauseElement && mAudioChannelAgent) {
     // If the element is being paused since we are navigating away from the
     // document, notify the audio channel agent.
-    NotifyAudioChannelAgent(false);
+    // Be careful to ignore this event during a docshell frame swap.
+    auto docShell = static_cast<nsDocShell*>(OwnerDoc()->GetDocShell());
+    if (!docShell) {
+      return;
+    }
+    if (!docShell->InFrameSwap()) {
+      NotifyAudioChannelAgent(false);
+    }
   }
 }
 

dom/ipc/TabChild.cpp

@@ -2429,11 +2429,18 @@ TabChild::RecvSwappedWithOtherRemoteLoader()
     return true;
   }
 
+  nsRefPtr<nsDocShell> docShell = static_cast<nsDocShell*>(ourDocShell.get());
+
   nsCOMPtr<EventTarget> ourEventTarget = ourWindow->GetParentTarget();
 
+  docShell->SetInFrameSwap(true);
+
   nsContentUtils::FirePageShowEvent(ourDocShell, ourEventTarget, false);
   nsContentUtils::FirePageHideEvent(ourDocShell, ourEventTarget);
   nsContentUtils::FirePageShowEvent(ourDocShell, ourEventTarget, true);
+
+  docShell->SetInFrameSwap(false);
+
   return true;
 }