Bug 1228564 - part 2 : check audio capturing when the agent is registered/unregistered. r=baku.

dom/html/HTMLMediaElement.cpp

@@ -114,31 +114,18 @@ using mozilla::net::nsMediaFragmentURIParser;
 class MOZ_STACK_CLASS AutoNotifyAudioChannelAgent
 {
   RefPtr<mozilla::dom::HTMLMediaElement> mElement;
-  bool mShouldNotify;
   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER;
 public:
-  AutoNotifyAudioChannelAgent(mozilla::dom::HTMLMediaElement* aElement,
-                              bool aNotify
+  AutoNotifyAudioChannelAgent(mozilla::dom::HTMLMediaElement* aElement
                               MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
     : mElement(aElement)
-    , mShouldNotify(aNotify)
   {
     MOZ_GUARD_OBJECT_NOTIFIER_INIT;
-    if (mShouldNotify) {
-      // The audio channel agent may not exist now.
-      if (mElement->MaybeCreateAudioChannelAgent()) {
-        mElement->NotifyAudioChannelAgent(false);
-      }
-    }
   }
+
   ~AutoNotifyAudioChannelAgent()
   {
-    if (mShouldNotify) {
-      // The audio channel agent is destroyed at this point.
-      if (mElement->MaybeCreateAudioChannelAgent()) {
-        mElement->NotifyAudioChannelAgent(true);
-      }
-    }
+    mElement->UpdateAudioChannelPlayingState();
   }
 };
 
@@ -3399,10 +3386,7 @@ void HTMLMediaElement::MetadataLoaded(const MediaInfo* aInfo,
   // If the element is gaining or losing an audio track, we need to notify
   // the audio channel agent so that the correct audio-playback events will
   // get dispatched.
-  bool audioTrackChanging = mMediaInfo.HasAudio() != aInfo->HasAudio();
-  AutoNotifyAudioChannelAgent autoNotify(this,
-                                         audioTrackChanging &&
-                                         mPlayingThroughTheAudioChannel);
+  AutoNotifyAudioChannelAgent autoNotify(this);
 
   mMediaInfo = *aInfo;
   mIsEncrypted = aInfo->IsEncrypted()
@@ -4761,6 +4745,11 @@ HTMLMediaElement::IsPlayingThroughTheAudioChannel() const
     return false;
   }
 
+  // If this element doesn't have any audio tracks.
+  if (!HasAudio()) {
+    return false;
+  }
+
   // The volume should not be ~0
   if (std::fabs(Volume()) <= 1e-7) {
     return false;
@@ -4816,15 +4805,6 @@ HTMLMediaElement::UpdateAudioChannelPlayingState()
 void
 HTMLMediaElement::NotifyAudioChannelAgent(bool aPlaying)
 {
-  // Don't do anything if this element doesn't have any audio tracks.
-  if (!HasAudio()) {
-    return;
-  }
-
-  // Immediately check if this should go to the MSG instead of the normal
-  // media playback route.
-  WindowAudioCaptureChanged();
-
   // This is needed to pass nsContentUtils::IsCallerChrome().
   // AudioChannel API should not called from content but it can happen that
   // this method has some content JS in its stack.
@@ -4995,17 +4975,17 @@ HTMLMediaElement::GetTopLevelPrincipal()
 }
 #endif // MOZ_EME
 
-NS_IMETHODIMP HTMLMediaElement::WindowAudioCaptureChanged()
+NS_IMETHODIMP HTMLMediaElement::WindowAudioCaptureChanged(bool aCapture)
 {
   MOZ_ASSERT(mAudioChannelAgent);
+  MOZ_ASSERT(HasAudio());
 
   if (!OwnerDoc()->GetInnerWindow()) {
     return NS_OK;
   }
-  bool captured = OwnerDoc()->GetInnerWindow()->GetAudioCaptured();
 
-  if (captured != mAudioCapturedByWindow) {
-    if (captured) {
+  if (aCapture != mAudioCapturedByWindow) {
+    if (aCapture) {
       mAudioCapturedByWindow = true;
       nsCOMPtr<nsPIDOMWindow> window =
         do_QueryInterface(OwnerDoc()->GetParentObject());
@@ -5041,7 +5021,7 @@ NS_IMETHODIMP HTMLMediaElement::WindowAudioCaptureChanged()
     }
   }
 
-   return NS_OK;
+  return NS_OK;
 }
 
 AudioTrackList*