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

content/renderer/media/renderer_webaudiodevice_impl.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 CONTENT_RENDERER_MEDIA_MEDIA_RENDERER_WEBAUDIODEVICE_IMPL_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_RENDERER_WEBAUDIODEVICE_IMPL_H_
 
 #include "base/memory/ref_counted.h"
 #include "media/base/audio_renderer_sink.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebAudioDevice.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebVector.h"
 
 class RendererWebAudioDeviceImpl
     : public WebKit::WebAudioDevice,
       public media::AudioRendererSink::RenderCallback {
  public:
   RendererWebAudioDeviceImpl(const media::AudioParameters& params,
                              WebKit::WebAudioDevice::RenderCallback* callback);
   virtual ~RendererWebAudioDeviceImpl();
 
   // WebKit::WebAudioDevice implementation.
   virtual void start();
   virtual void stop();
   virtual double sampleRate();
 
   // AudioRendererSink::RenderCallback implementation.
-  virtual int Render(media::AudioBus* audio_bus,
+  virtual int Render(media::AudioBus* dest,
                      int audio_delay_milliseconds) OVERRIDE;
+
+  virtual void RenderIO(media::AudioBus* source,
+                        media::AudioBus* dest,
+                        int audio_delay_milliseconds) OVERRIDE;
+
   virtual void OnRenderError() OVERRIDE;
 
  private:
   scoped_refptr<media::AudioRendererSink> audio_device_;
   bool is_running_;
 
   // Weak reference to the callback into WebKit code.
   WebKit::WebAudioDevice::RenderCallback* client_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererWebAudioDeviceImpl);
 };
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_RENDERER_WEBAUDIODEVICE_IMPL_H_