Mute audio for Spitzer playbacks that haven't received focus yet.

content/renderer/media/renderer_webmediaplayer_delegate.cc

Index: content/renderer/media/renderer_webmediaplayer_delegate.cc
diff --git a/content/renderer/media/renderer_webmediaplayer_delegate.cc b/content/renderer/media/renderer_webmediaplayer_delegate.cc
index 2c7054648da8bc4c9c4da3fc1fe9fe8dba8df94c..c6b593231d8ffc00d7a4092de1456a3fcd561130 100644
--- a/content/renderer/media/renderer_webmediaplayer_delegate.cc
+++ b/content/renderer/media/renderer_webmediaplayer_delegate.cc
@@ -19,7 +19,9 @@ RendererWebMediaPlayerDelegate::RendererWebMediaPlayerDelegate(
 RendererWebMediaPlayerDelegate::~RendererWebMediaPlayerDelegate() {}
 
 int RendererWebMediaPlayerDelegate::AddObserver(Observer* observer) {
-  return id_map_.Add(observer);
+  const int delegate_id = id_map_.Add(observer);
+  MuteObserverUntilPlaybackFocusApproved(delegate_id);
+  return delegate_id;
 }
 
 void RendererWebMediaPlayerDelegate::RemoveObserver(int delegate_id) {
@@ -41,12 +43,14 @@ void RendererWebMediaPlayerDelegate::DidPlay(int delegate_id,
 void RendererWebMediaPlayerDelegate::DidPause(int delegate_id,
                                               bool reached_end_of_stream) {
   DCHECK(id_map_.Lookup(delegate_id));
+  MuteObserverUntilPlaybackFocusApproved(delegate_id);
   Send(new MediaPlayerDelegateHostMsg_OnMediaPaused(routing_id(), delegate_id,
                                                     reached_end_of_stream));
 }
 
 void RendererWebMediaPlayerDelegate::PlayerGone(int delegate_id) {
   DCHECK(id_map_.Lookup(delegate_id));
+  MuteObserverUntilPlaybackFocusApproved(delegate_id);
   Send(new MediaPlayerDelegateHostMsg_OnMediaDestroyed(routing_id(),
                                                        delegate_id));
 }
@@ -98,4 +102,11 @@ void RendererWebMediaPlayerDelegate::OnMediaDelegateVolumeMultiplierUpdate(
     observer->OnVolumeMultiplierUpdate(multiplier);
 }
 
+void RendererWebMediaPlayerDelegate::MuteObserverUntilPlaybackFocusApproved(
+    int delegate_id) {
+#if defined(OS_ANDROID)
+  id_map_.Lookup(delegate_id)->OnVolumeMultiplierUpdate(0);
+#endif
+}
+
 }  // namespace media