Implement renderer AudioDevice API for low-latency audio output...

chrome/renderer/renderer_webaudiodevice_impl.h

+// Copyright (c) 2010 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 CHROME_RENDERER_RENDERER_WEBAUDIODEVICE_IMPL_H_
+#define CHROME_RENDERER_RENDERER_WEBAUDIODEVICE_IMPL_H_
+
+#include <vector>
+
+#include "base/scoped_ptr.h"
+#include "chrome/renderer/audio_device.h"
+#include "third_party/WebKit/WebKit/chromium/public/WebAudioDevice.h"
+#include "third_party/WebKit/WebKit/chromium/public/WebVector.h"
+
+class RendererWebAudioDeviceImpl : public WebKit::WebAudioDevice,
+                                   public AudioDevice::RenderCallback {
+ public:
+  RendererWebAudioDeviceImpl(size_t buffer_size,
+                             int channels,
+                             double sample_rate,
+                             WebKit::WebAudioDevice::RenderCallback* callback);
+  virtual ~RendererWebAudioDeviceImpl();
+
+  // WebKit::WebAudioDevice implementation.
+  virtual void start();
+  virtual void stop();
+
+  // AudioDevice::RenderCallback implementation.
+  void Render(const std::vector<float*>& audio_data, size_t number_of_frames);
+
+ private:
+  scoped_ptr<AudioDevice> audio_device_;
+
+  // Weak reference to the callback into WebKit code.
+  WebKit::WebAudioDevice::RenderCallback* client_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(RendererWebAudioDeviceImpl);
+};
+
+#endif  // CHROME_RENDERER_RENDERER_WEBAUDIODEVICE_IMPL_H_