Change the way audio mixer gets "pending bytes" (amount of data currently buffered

media/audio/audio_output_mixer.h

 // Copyright (c) 2012 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.
 
 // AudioOutputMixer is a class that implements browser-side audio mixer.
 // AudioOutputMixer implements both AudioOutputDispatcher and
 // AudioSourceCallback interfaces.
 
 #ifndef MEDIA_AUDIO_AUDIO_OUTPUT_MIXER_H_
 #define MEDIA_AUDIO_AUDIO_OUTPUT_MIXER_H_
@@ skipping 65 matching lines @@
   scoped_ptr<AudioOutputStream> physical_stream_;
 
   // Temporary buffer used when mixing. Allocated in the constructor
   // to avoid constant allocation/deallocation in the callback.
   scoped_array<uint8> mixer_data_;
 
   // Used to post delayed tasks to ourselves that we cancel inside Shutdown().
   base::WeakPtrFactory<AudioOutputMixer> weak_this_;
   base::DelayTimer<AudioOutputMixer> close_timer_;
 
+  // Size of data in all in-flight buffers.
+  int pending_bytes_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioOutputMixer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_OUTPUT_MIXER_H_