Added volume adjust sound behind the flag.

media/audio/sounds/audio_stream_handler.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_AUDIO_SOUNDS_AUDIO_STREAM_HANDLER_H_
 #define MEDIA_AUDIO_SOUNDS_AUDIO_STREAM_HANDLER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/strings/string_piece.h"
@@ skipping 24 matching lines @@
   };
 
   // C-tor for AudioStreamHandler. |wav_data| should be a raw
   // uncompressed WAVE data which will be sent to the audio manager.
   explicit AudioStreamHandler(const base::StringPiece& wav_data);
   virtual ~AudioStreamHandler();
 
   // Returns true iff AudioStreamHandler is correctly initialized;
   bool IsInitialized() const;
 
-  // Stops any previous playback if it's still not completed and
-  // starts new playback. Volume level will be set according to
-  // current settings and won't be changed during playback. Returns
-  // true iff new playback was successfully started.
+  // Plays sound.  Volume level will be set according to current settings
+  // and won't be changed during playback. Returns true iff new playback
+  // was successfully started.
+  //
+  // NOTE: if current playback isn't at end of stream, playback request
+  // is dropped, but true is returned.
   bool Play();
 
   // Stops current playback.
   void Stop();
 
   const WavAudioHandler& wav_audio_handler() const { return wav_audio_; }
 
  private:
   friend class AudioStreamHandlerTest;
   friend class SoundsManagerTest;
 
   class AudioStreamContainer;
 
   static void SetObserverForTesting(TestObserver* observer);
   static void SetAudioSourceForTesting(
       AudioOutputStream::AudioSourceCallback* source);
 
   WavAudioHandler wav_audio_;
   scoped_ptr<AudioStreamContainer> stream_;
 
   bool initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioStreamHandler);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_SOUNDS_AUDIO_STREAM_HANDLER_H_