Associate audio streams with their source/destination RenderView.

content/renderer/media/renderer_audio_output_device.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.
+//
+// Subclass of media::AudioOutputDevice to support additional concepts within
+// the content component.  Use AudioDeviceFactory to instantiate this class.

[scherkus (not reviewing), 2012/11/30 22:09:43]

nit: while chromium is overall inconsistent, most media code sticks these types
of comments by the class itself

[miu, 2012/12/01 00:40:17]

Done.

+
+#ifndef CONTENT_RENDERER_MEDIA_RENDERER_AUDIO_OUTPUT_DEVICE_H_
+#define CONTENT_RENDERER_MEDIA_RENDERER_AUDIO_OUTPUT_DEVICE_H_
+
+#include "base/memory/ref_counted.h"
+#include "media/audio/audio_output_device.h"
+
+namespace base {
+class MessageLoopProxy;
+}
+
+namespace content {
+
+class AudioDeviceFactory;
+class AudioMessageFilter;
+
+class RendererAudioOutputDevice
+    : NON_EXPORTED_BASE(public media::AudioOutputDevice) {
+ public:
+  // Set the source of the rendered audio data to the RenderView specified by
+  // |render_view_id|.  Callers should keep in mind that the RenderView which
+  // caused the instantiation of RendererAudioOutputDevice might not necessarily
+  // be same as the RenderView which actually renders the audio data.
+  void SetSourceRenderView(int render_view_id);
+
+  virtual void Start() OVERRIDE;
+  virtual void Stop() OVERRIDE;
+
+ protected:
+  friend class AudioDeviceFactory;
+
+  // Creates an uninitialized RendererAudioOutputDevice.  Clients must call
+  // Initialize() before using.
+  RendererAudioOutputDevice(
+      AudioMessageFilter* message_filter,
+      const scoped_refptr<base::MessageLoopProxy>& io_loop);
+
+ private:
+  // Note: Base class is ref-counted.

[scherkus (not reviewing), 2012/11/30 22:09:43]

no need -- ref-counting is (sadly) common enough

[miu, 2012/12/01 00:40:17]

Done.

+  virtual ~RendererAudioOutputDevice();
+
+  void OnStart();
+  void OnStop();
+  void OnSourceChange(int render_view_id);
+
+  int source_render_view_id_;
+  bool is_after_stream_created_;
+
+  DISALLOW_COPY_AND_ASSIGN(RendererAudioOutputDevice);

[scherkus (not reviewing), 2012/11/30 22:09:43]

s/C_A_A/I_C/

[miu, 2012/12/01 00:40:17]

Done.

+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MEDIA_RENDERER_AUDIO_OUTPUT_DEVICE_H_