Makes AudioOutputProxy -> AudioOutputDispatcher reference weak.

media/audio/audio_output_dispatcher.h

Index: media/audio/audio_output_dispatcher.h
diff --git a/media/audio/audio_output_dispatcher.h b/media/audio/audio_output_dispatcher.h
index f94f95f65389c657cef60a3393acc0ceebbd45f0..22a47dde613ae1a58cc47934634d6eeb2d45f75b 100644
--- a/media/audio/audio_output_dispatcher.h
+++ b/media/audio/audio_output_dispatcher.h
@@ -38,6 +38,11 @@ class MEDIA_EXPORT AudioOutputDispatcher {
                         const std::string& device_id);
   virtual ~AudioOutputDispatcher();
 
+  // Creates an instance of AudioOutputProxy, which uses |this| as dispatcher.
+  // The client owns the returned pointer, which can be deleted using
+  // AudioOutputProxy::Close.
+  virtual AudioOutputProxy* CreateStreamProxy() = 0;
+
   // Called by AudioOutputProxy to open the stream.
   // Returns false, if it fails to open it.
   virtual bool OpenStream() = 0;