Switch OnMoreData() to use AudioBus.

media/audio/linux/alsa_output.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.
 //
 // Creates an output stream based on the ALSA PCM interface.
 //
 // On device write failure, the stream will move itself to an invalid state.
 // No more data will be pulled from the data source, or written to the device.
 // All calls to public API functions will either no-op themselves, or return an
 // error if possible.  Specifically, If the stream is in an error state, Open()
@@ skipping 134 matching lines @@
   bool IsOnAudioThread() const;
 
   // API for Proxying calls to the AudioSourceCallback provided during
   // Start().
   //
   // TODO(ajwong): This is necessary because the ownership semantics for the
   // |source_callback_| object are incorrect in AudioRenderHost. The callback
   // 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
   // release ownership of the currently registered callback.
   void set_source_callback(AudioSourceCallback* callback);
 
   // Configuration constants from the constructor.  Referenceable by all threads
   // since they are constants.
   const std::string requested_device_name_;
   const snd_pcm_format_t pcm_format_;
@@ skipping 38 matching lines @@
   // bound by its lifetime.
   base::WeakPtrFactory<AlsaPcmOutputStream> weak_factory_;
 
   InternalState state_;
   float volume_;  // Volume level from 0.0 to 1.0.
 
   AudioSourceCallback* source_callback_;
 
   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);
 };
 
 MEDIA_EXPORT std::ostream& operator<<(std::ostream& os,
                                       AlsaPcmOutputStream::InternalState);
 
 };  // namespace media
 
 #endif  // MEDIA_AUDIO_LINUX_ALSA_OUTPUT_H_