Mute audio when volume is zero on Android.

media/audio/audio_manager_base.h

Index: media/audio/audio_manager_base.h
diff --git a/media/audio/audio_manager_base.h b/media/audio/audio_manager_base.h
index 860ed5c9248fe80cc2283a0d422949b42db4e836..5b789a74eeea43a0301d5dc809fafa56ec7c7277 100644
--- a/media/audio/audio_manager_base.h
+++ b/media/audio/audio_manager_base.h
@@ -154,6 +154,12 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   int input_stream_count() { return num_input_streams_; }
   int output_stream_count() { return num_output_streams_; }
 
+ protected:
+  // The message loop of the audio thread this object runs on. Used for internal
+  // tasks which run on the audio thread even after Shutdown() has been started
+  // and GetMessageLoop() starts returning NULL.
+  scoped_refptr<base::MessageLoopProxy> message_loop_;

[tommi (sloooow) - chröme, 2013/12/02 18:36:00]

I don't think we need this change so it would be great to revert (no other
platform needs it). Instead use GetMessageLoop.

[wjia(left Chromium), 2013/12/02 21:49:49]

Done.

+
  private:
   struct DispatcherParams;
   typedef ScopedVector<DispatcherParams> AudioOutputDispatchers;
@@ -182,11 +188,6 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   // Thread used to interact with audio streams created by this audio manager.
   base::Thread audio_thread_;
 
-  // The message loop of the audio thread this object runs on. Used for internal
-  // tasks which run on the audio thread even after Shutdown() has been started
-  // and GetMessageLoop() starts returning NULL.
-  scoped_refptr<base::MessageLoopProxy> message_loop_;
-
   // Map of cached AudioOutputDispatcher instances.  Must only be touched
   // from the audio thread (no locking).
   AudioOutputDispatchers output_dispatchers_;