First step towards moving AudioDevice from content/ to media/audio.

content/renderer/media/audio_device_factory.h

Index: content/renderer/media/audio_device_factory.h
diff --git a/content/renderer/media/audio_device_factory.h b/content/renderer/media/audio_device_factory.h
index b15e96701c94e67eb3c232d4361dbc9139a307ad..14433ce91b7bc12115691ff654ed2cf558427367 100644
--- a/content/renderer/media/audio_device_factory.h
+++ b/content/renderer/media/audio_device_factory.h
@@ -12,6 +12,8 @@ namespace media {
 class AudioRendererSink;
 }
 
+class AudioInputDevice;
+
 namespace content {
 
 // A factory for creating AudioRendererSinks. There is a global factory
@@ -23,15 +25,23 @@ class CONTENT_EXPORT AudioDeviceFactory {
   // Creates an AudioRendererSink using the currently registered factory,
   // or the default one if no factory is registered. Ownership of the returned
   // pointer will be passed to the caller.
- static media::AudioRendererSink* Create();
+ static media::AudioRendererSink* NewOutputDevice();
+
+ // TODO(henrika): Update AudioInputDevice to inherit from an interface
+ // similar to AudioRendererSink, but for input.  Same for the callback
+ // interfaces.
+ static AudioInputDevice* NewInputDevice();
 
  protected:
   AudioDeviceFactory();
   virtual ~AudioDeviceFactory();
 
-  // You can derive from this class and specify an implementation for this
-  // function to create a different kind of AudioRendererSink for testing.
-  virtual media::AudioRendererSink* CreateAudioDevice() = 0;
+  // You can derive from this class and specify an implementation for these
+  // functions to provide alternate audio device implementations.
+  // If the return value of either of these function is NULL, we fall back
+  // on the default implementation.
+  virtual media::AudioRendererSink* CreateOutputDevice() = 0;
+  virtual AudioInputDevice* CreateInputDevice() = 0;
 
  private:
   // The current globally registered factory. This is NULL when we should