Allow audio system to handle synchronized low-latency audio I/O

media/audio/simple_sources.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.
 
 #ifndef MEDIA_AUDIO_SIMPLE_SOURCES_H_
 #define MEDIA_AUDIO_SIMPLE_SOURCES_H_
 
 #include "base/synchronization/lock.h"
 #include "media/audio/audio_io.h"
 #include "media/base/seekable_buffer.h"
@@ skipping 11 matching lines @@
   virtual ~SineWaveAudioSource() {}
 
   // Return up to |cap| samples of data via OnMoreData().  Use Reset() to
   // allow more data to be served.
   void CapSamples(int cap);
   void Reset();
 
   // Implementation of AudioSourceCallback.
   virtual int OnMoreData(AudioBus* audio_bus,
                          AudioBuffersState audio_buffers) OVERRIDE;
+  virtual int OnMoreIOData(AudioBus* source,
+                           AudioBus* dest,
+                           AudioBuffersState audio_buffers) OVERRIDE;
   virtual void OnError(AudioOutputStream* stream, int code) OVERRIDE;
 
  protected:
   int channels_;
   double f_;
   int time_state_;
   int cap_;
   base::Lock time_lock_;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_SIMPLE_SOURCES_H_