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

media/audio/audio_output_resampler.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_AUDIO_OUTPUT_RESAMPLER_H_
 #define MEDIA_AUDIO_AUDIO_OUTPUT_RESAMPLER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
@@ skipping 36 matching lines @@
   virtual bool OpenStream() OVERRIDE;
   virtual bool StartStream(AudioOutputStream::AudioSourceCallback* callback,
                            AudioOutputProxy* stream_proxy) OVERRIDE;
   virtual void StopStream(AudioOutputProxy* stream_proxy) OVERRIDE;
   virtual void StreamVolumeSet(AudioOutputProxy* stream_proxy,
                                double volume) OVERRIDE;
   virtual void CloseStream(AudioOutputProxy* stream_proxy) OVERRIDE;
   virtual void Shutdown() OVERRIDE;
 
   // AudioSourceCallback interface.
-  virtual int OnMoreData(AudioBus* audio_bus,
+  virtual int OnMoreData(AudioBus* dest,
                          AudioBuffersState buffers_state) OVERRIDE;
+  virtual int OnMoreIOData(AudioBus* source,
+                           AudioBus* dest,
+                           AudioBuffersState buffers_state) OVERRIDE;
   virtual void OnError(AudioOutputStream* stream, int code) OVERRIDE;
   virtual void WaitTillDataReady() OVERRIDE;
 
  private:
   friend class base::RefCountedThreadSafe<AudioOutputResampler>;
   virtual ~AudioOutputResampler();
 
   // Called by MultiChannelResampler when more data is necessary.
   void ProvideInput(AudioBus* audio_bus);
 
@@ skipping 37 matching lines @@
   // Total number of bytes (in terms of output parameters) stored in resampler
   // or FIFO buffers which have not been sent to the audio device.
   int outstanding_audio_bytes_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioOutputResampler);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_OUTPUT_RESAMPLER_H_