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..009d1a0991291d48d5f2fb992d5362fc627cceaa 100644
--- a/media/audio/sounds/audio_stream_handler.h
+++ b/media/audio/sounds/audio_stream_handler.h
@@ -11,12 +11,13 @@
 #include "base/threading/non_thread_safe.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_parameters.h"
-#include "media/audio/sounds/wav_audio_handler.h"
+#include "media/audio/sounds/wav_parser.h"
 #include "media/base/media_export.h"
 
 namespace media {
 
 class AudioManager;
+class WavReader;
 
 // This class sends a sound to the audio manager.
 class MEDIA_EXPORT AudioStreamHandler : public base::NonThreadSafe {
@@ -30,6 +31,9 @@ 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;
   };
@@ -51,7 +55,7 @@ class MEDIA_EXPORT AudioStreamHandler : public base::NonThreadSafe {
   // Stops current playback.
   void Stop();
 
-  const WavAudioHandler& wav_audio_handler() const { return wav_audio_; }
+  const WavParser& wav_parser() const { return wav_parser_; }
 
  private:
   friend class AudioStreamHandlerTest;
@@ -62,8 +66,12 @@ class MEDIA_EXPORT AudioStreamHandler : public base::NonThreadSafe {
   static void SetObserverForTesting(TestObserver* observer);
   static void SetAudioSourceForTesting(
       AudioOutputStream::AudioSourceCallback* source);
+  void SetWavReaderForTesting(WavReader* reader);
+  void AllowReplayOnceForTesting();
+
+  void StopAfterDelay();
 
-  WavAudioHandler wav_audio_;
+  WavParser wav_parser_;
   scoped_ptr<AudioStreamContainer> stream_;
 
   bool initialized_;