Adds AudioDevice factory for all audio clients in Chrome

content/renderer/media/audio_device.h

Index: content/renderer/media/audio_device.h
diff --git a/content/renderer/media/audio_device.h b/content/renderer/media/audio_device.h
index 74b28d33d8558d2a8ed97f03f7ff0d5ecc6a23d3..bc26361e5f29c140ae68cbcc4e26febbda59df57 100644
--- a/content/renderer/media/audio_device.h
+++ b/content/renderer/media/audio_device.h
@@ -76,6 +76,8 @@
 #include "media/audio/audio_parameters.h"
 #include "media/base/audio_renderer_sink.h"
 
+class AudioMessageFilter;
+
 namespace media {
 class AudioParameters;
 }
@@ -88,9 +90,7 @@ class CONTENT_EXPORT AudioDevice
   // Methods called on main render thread -------------------------------------
 
   // Minimal constructor where Initialize() must be called later.
-  AudioDevice();
-
-  AudioDevice(const media::AudioParameters& params, RenderCallback* callback);
+  explicit AudioDevice(AudioMessageFilter* filter);

[Chris Rogers, 2012/06/14 17:41:44]

This is leaking internal implementation details for AudioDevice into the public
interface which is not a good idea.  The whole purpose of the AudioDevice
interface is to shield the client from any particular low-level details such as
this.  With this change, any client of AudioDevice must now get entangled into
AudioMessageFilters.

[tommi (sloooow) - chröme, 2012/06/16 09:09:06]

AudioDevice is the implementation, media::AudioRendererSink is the interface
(which btw should have been named media::AudioRendererSinkInterface in
accordance with the style guide).  Unless this constructor is a part of the
interface, then there's nothing being leaked.

 
   // AudioRendererSink implementation.
   virtual void Initialize(const media::AudioParameters& params,