Associate audio streams with their source/destination RenderView.

media/audio/audio_output_device.h

Index: media/audio/audio_output_device.h
diff --git a/media/audio/audio_output_device.h b/media/audio/audio_output_device.h
index fe4459cc5018d411041b39c49a3e4f35a90187e6..499eaa1a9e8691db113f5b112e3d995b1863375d 100644
--- a/media/audio/audio_output_device.h
+++ b/media/audio/audio_output_device.h
@@ -99,11 +99,12 @@ class MEDIA_EXPORT AudioOutputDevice
 
   // Creates an uninitialized AudioOutputDevice. Clients must call Initialize()
   // before using.
-  // TODO(tommi): When all dependencies on |content| have been removed
-  // from AudioOutputDevice, move this class over to media/audio.
   AudioOutputDevice(AudioOutputIPC* ipc,
                     const scoped_refptr<base::MessageLoopProxy>& io_loop);
 
+  // Returns the stream id used with the AudioOutputIPC interface.
+  int stream_id() const;
+
  protected:
   // Magic required by ref_counted.h to avoid any code deleting the object
   // accidentally while there are references to it.
@@ -111,10 +112,19 @@ class MEDIA_EXPORT AudioOutputDevice
   virtual ~AudioOutputDevice();
 
  private:
+  enum State {
+    kIpcClosed,  // No more IPCs can take place.

[scherkus (not reviewing), 2012/11/27 22:55:26]

chromium has decreed SHOUTING_STYLE for enum constants:
https://groups.google.com/a/chromium.org/d/topic/chromium-dev/RxEyIrolvs0/dis...

[miu, 2012/11/28 07:26:20]

Done.

+    kIdle,  // Not started.
+    kCreatingStream,  // Waiting for OnStreamCreated() to be called back.
+    kPaused,  // Paused.  OnStreamCreated() has been called.  Can Play()/Stop().
+    kPlaying,  // Playing back.  Can Pause()/Stop().
+  };
+
   // Methods called on IO thread ----------------------------------------------
   // The following methods are tasks posted on the IO thread that needs to
   // be executed on that thread. They interact with AudioMessageFilter and
   // sends IPC messages on that thread.
+  void RegisterDelegateOnIOThread(AudioOutputIPC* ipc);
   void CreateStreamOnIOThread(const AudioParameters& params,
                               int input_channels);
   void PlayOnIOThread();
@@ -136,21 +146,19 @@ class MEDIA_EXPORT AudioOutputDevice
 
   // A pointer to the IPC layer that takes care of sending requests over to
   // the AudioRendererHost.
-  AudioOutputIPC* ipc_;
+  base::WeakPtr<AudioOutputIPC> ipc_;
 
   // Our stream ID on the message filter. Only accessed on the IO thread.
   // Must only be modified on the IO thread.
   int stream_id_;
 
+  // Current state (must only be accessed from the IO thread).  See comments for
+  // State enum above.
+  State state_;
+
   // State of Play() / Pause() calls before OnStreamCreated() is called.
   bool play_on_start_;
 
-  // Set to |true| when OnStreamCreated() is called.
-  // Set to |false| when ShutDownOnIOThread() is called.
-  // This is for use with play_on_start_ to track Play() / Pause() state.
-  // Must only be touched from the IO thread.
-  bool is_started_;
-
   // Our audio thread callback class.  See source file for details.
   class AudioThreadCallback;