Added volume adjust sound behind the flag.

media/audio/sounds/audio_stream_handler.h

Index: media/audio/sounds/audio_stream_handler.h
diff --git a/media/audio/sounds/audio_stream_handler.h b/media/audio/sounds/audio_stream_handler.h
index 7c63a24f0348f3fb4228ed1bacde363ad773a772..617a11ec3128c7046a377f8046b39fa987ef3be6 100644
--- a/media/audio/sounds/audio_stream_handler.h
+++ b/media/audio/sounds/audio_stream_handler.h
@@ -30,6 +30,9 @@ class MEDIA_EXPORT AudioStreamHandler : public base::NonThreadSafe {
     // Called when AudioOutputStreamProxy::Start() was successfully called.
     virtual void OnPlay() = 0;
 
+    // Called when current sound is replayed.
+    virtual void OnReplay() = 0;
+
     // Called when AudioOutputStreamProxy::Stop() was successfully called.
     virtual void OnStop(size_t cursor) = 0;
   };
@@ -62,6 +65,9 @@ class MEDIA_EXPORT AudioStreamHandler : public base::NonThreadSafe {
   static void SetObserverForTesting(TestObserver* observer);
   static void SetAudioSourceForTesting(
       AudioOutputStream::AudioSourceCallback* source);
+  void AllowReplayOnceForTesting();
+
+  void StopAfterDelay();
 
   WavAudioHandler wav_audio_;
   scoped_ptr<AudioStreamContainer> stream_;