Adds AudioDevice factory for all audio clients in Chrome

content/renderer/media/audio_message_filter.h

Index: content/renderer/media/audio_message_filter.h
diff --git a/content/renderer/media/audio_message_filter.h b/content/renderer/media/audio_message_filter.h
index 40faeabec271c8d6fbd2c8c0ec3d5c4e221d9340..85d12fd5fb72edc5b80269fe441915f083f1b5dd 100644
--- a/content/renderer/media/audio_message_filter.h
+++ b/content/renderer/media/audio_message_filter.h
@@ -39,6 +39,9 @@ class CONTENT_EXPORT AudioMessageFilter
 
   AudioMessageFilter();
 
+  // Getter for the one AudioMessageFilter object.
+  static AudioMessageFilter* current();

[jam, 2012/06/27 15:56:29]

per style guide, since the implementation is in the cc file this should be
CamelCase, i.e. Get(). The current() naming for RenderThread where I assume you
got this is incorrect (it was a holdover from when it was inlined) and just
needs to update all the code.

[henrika (OOO until Aug 14), 2012/06/27 17:54:47]

Got it. Not GetCurrent() then?

[jam, 2012/06/27 18:03:58]

current() was named like because initially there was a thought that there would
be different RenderThread objects in the same renderer process, so current()
would give the current one for the given thread. but that never panned out.

Get() is more consistent with getters

[henrika (OOO until Aug 14), 2012/06/28 11:36:01]

Done.

+
   // Add a delegate to the map and return id of the entry.
   int32 AddDelegate(Delegate* delegate);
 
@@ -75,6 +78,10 @@ class CONTENT_EXPORT AudioMessageFilter
   // changed.
   void OnStreamStateChanged(int stream_id, AudioStreamState state);
 
+  // The singleton instance for this filter.
+  // Should only be accessed on the main renderer thread.

[jam, 2012/06/27 15:56:29]

nit: i thought the whole point of exposing the getter above is that it'll called
on multiple threads?

[henrika (OOO until Aug 14), 2012/06/27 17:54:47]

I do need a vacation. Thanks.

[henrika (OOO until Aug 14), 2012/06/28 11:36:01]

Done.

+  static AudioMessageFilter* filter_;
+
   // A map of stream ids to delegates.
   IDMap<Delegate> delegates_;