Switch OnMoreData() to use AudioBus.

media/audio/linux/alsa_output.h

Index: media/audio/linux/alsa_output.h
diff --git a/media/audio/linux/alsa_output.h b/media/audio/linux/alsa_output.h
index 741582120353b8a95ef2ba24155637808e9e3d17..736015e530fdf62d0fb7e9232a3c1230c7ece90a 100644
--- a/media/audio/linux/alsa_output.h
+++ b/media/audio/linux/alsa_output.h
@@ -152,9 +152,7 @@ class MEDIA_EXPORT AlsaPcmOutputStream : public AudioOutputStream {
   // is passed into the output stream, but ownership is not transfered which
   // requires a synchronization on access of the |source_callback_| to avoid
   // using a deleted callback.
-  uint32 RunDataCallback(uint8* dest,
-                         uint32 max_size,
-                         AudioBuffersState buffers_state);
+  int RunDataCallback(AudioBus* audio_bus, AudioBuffersState buffers_state);
   void RunErrorCallback(int code);
 
   // Changes the AudioSourceCallback to proxy calls to.  Pass in NULL to
@@ -213,6 +211,9 @@ class MEDIA_EXPORT AlsaPcmOutputStream : public AudioOutputStream {
 
   base::Time last_fill_time_;  // Time for the last OnMoreData() callback.
 
+  // Container for retrieving data from AudioSourceCallback::OnMoreData().
+  scoped_ptr<AudioBus> audio_bus_;
+
   DISALLOW_COPY_AND_ASSIGN(AlsaPcmOutputStream);
 };