Bug 1322505 - part2 : reset suspend type for blocked media after calling media.pause(). r=baku

If the blocked media is paused before resuming it, we should not resume it again
after the tab is visible. The way to achieve that is to unregister the agent so
AudioChannelService can't resume that media because we have disconnected their
relationship.

MozReview-Commit-ID: 6Dq4K9hVsU0

--HG--
extra : rebase_source : 1a1f17e09e5ab85e18b4bce9d009ab51ccaa7aab

dom/html/HTMLMediaElement.cpp

@@ -654,15 +654,32 @@ public:
     }
   }
 
+  bool
+  ShouldResetSuspend() const
+  {
+    // The disposable-pause should be clear after media starts playing.
+    if (!mOwner->Paused() &&
+        mSuspended == nsISuspendedTypes::SUSPENDED_PAUSE_DISPOSABLE) {
+      return true;
+    }
+
+    // If the blocked media is paused, we don't need to resume it. We reset the
+    // mSuspended in order to unregister the agent.
+    if (mOwner->Paused() &&
+        mSuspended == nsISuspendedTypes::SUSPENDED_BLOCK) {
+      return true;
+    }
+
+    return false;
+  }
+
   void
   NotifyPlayStateChanged()
   {
     MOZ_ASSERT(!mIsShutDown);
-    // When owner's play state changed, we should reset the suspend type. If
-    // owner is playing, the suspend type should be 'NONE_SUSPENDED', and if
-    // owner paused, the suspend type also needs to be reset because the agent
-    // maybe need to be unregistered.
-    SetSuspended(nsISuspendedTypes::NONE_SUSPENDED);
+    if (ShouldResetSuspend()) {
+      SetSuspended(nsISuspendedTypes::NONE_SUSPENDED);
+    }
     UpdateAudioChannelPlayingState();
   }
 
@@ -881,7 +898,7 @@ private:
     if (!IsSuspended()) {
       MOZ_LOG(AudioChannelService::GetAudioChannelLog(), LogLevel::Debug,
              ("HTMLMediaElement::AudioChannelAgentCallback, ResumeFromAudioChannel, "
-              "this = %p, Error : resume without suspended!\n", this));
+              "this = %p, don't need to be resumed!\n", this));
       return;
     }
 
@@ -2758,7 +2775,9 @@ HTMLMediaElement::Pause(ErrorResult& aRv)
   // We changed mPaused and mAutoplaying which can affect AddRemoveSelfReference
   AddRemoveSelfReference();
   UpdateSrcMediaStreamPlaying();
-  UpdateAudioChannelPlayingState();
+  if (mAudioChannelWrapper) {
+    mAudioChannelWrapper->NotifyPlayStateChanged();
+  }
 
   if (!oldPaused) {
     FireTimeUpdate(false);