Modifies AudioInputCallback::OnData and use media::AudioBus instead of plain byte vector (Relanding)

media/audio/mac/audio_input_mac.h

Index: media/audio/mac/audio_input_mac.h
diff --git a/media/audio/mac/audio_input_mac.h b/media/audio/mac/audio_input_mac.h
index e8f77c706aeaf413cce9a9a535b341b36d65ce38..a6e897e061080bb8cc8f092ac97aba68d6090d70 100644
--- a/media/audio/mac/audio_input_mac.h
+++ b/media/audio/mac/audio_input_mac.h
@@ -16,6 +16,7 @@
 
 namespace media {
 
+class AudioBus;
 class AudioManagerMac;
 
 // Implementation of AudioInputStream for Mac OS X using the audio queue service
@@ -83,6 +84,8 @@ class PCMQueueInAudioInputStream : public AudioInputStream {
   // Used to defer Start() to workaround http://crbug.com/160920.
   base::CancelableClosure deferred_start_cb_;
 
+  scoped_ptr<media::AudioBus> audio_bus_;
+
   DISALLOW_COPY_AND_ASSIGN(PCMQueueInAudioInputStream);
 };