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

content/renderer/media/audio_input_device.h

Index: content/renderer/media/audio_input_device.h
diff --git a/content/renderer/media/audio_input_device.h b/content/renderer/media/audio_input_device.h
index 8ef72b7e277704866cce16215f96b760ab671ad3..1d0e066928b426f02bedfffb85f59f68e2a60273 100644
--- a/content/renderer/media/audio_input_device.h
+++ b/content/renderer/media/audio_input_device.h
@@ -87,7 +87,7 @@
 // OnCaptureStopped etc.) and ensure that we can deliver these notifications
 // to any clients using this class.
 class CONTENT_EXPORT AudioInputDevice
-    : public AudioInputMessageFilter::Delegate,
+    : NON_EXPORTED_BASE(public media::AudioInputDeviceIPCDelegate),
       NON_EXPORTED_BASE(public ScopedLoopObserver),
       public base::RefCountedThreadSafe<AudioInputDevice> {
  public:
@@ -156,13 +156,15 @@ class CONTENT_EXPORT AudioInputDevice
   void SetAutomaticGainControl(bool enabled);
 
   // Methods called on IO thread ----------------------------------------------
-  // AudioInputMessageFilter::Delegate impl., called by AudioInputMessageFilter.
+  // media::AudioInputDeviceIPCDelegate implementation.
   virtual void OnStreamCreated(base::SharedMemoryHandle handle,
                                base::SyncSocket::Handle socket_handle,
                                uint32 length) OVERRIDE;
   virtual void OnVolume(double volume) OVERRIDE;
-  virtual void OnStateChanged(AudioStreamState state) OVERRIDE;
+  virtual void OnStateChanged(
+      media::AudioInputDeviceIPCDelegate::State state) OVERRIDE;
   virtual void OnDeviceReady(const std::string& device_id) OVERRIDE;
+  virtual void OnIPCClosed() OVERRIDE;
 
  protected:
   virtual ~AudioInputDevice();
@@ -181,8 +183,6 @@ class CONTENT_EXPORT AudioInputDevice
   void SetVolumeOnIOThread(double volume);
   void SetAutomaticGainControlOnIOThread(bool enabled);
 
-  void Send(IPC::Message* message);
-
   // MessageLoop::DestructionObserver implementation for the IO loop.
   // If the IO loop dies before we do, we shut down the audio thread from here.
   virtual void WillDestroyCurrentMessageLoop() OVERRIDE;
@@ -193,11 +193,7 @@ class CONTENT_EXPORT AudioInputDevice
   CaptureCallback* callback_;
   CaptureEventHandler* event_handler_;
 
-  // The current volume scaling [0.0, 1.0] of the audio stream.
-  double volume_;
-
-  // Cached audio input message filter (lives on the main render thread).
-  scoped_refptr<AudioInputMessageFilter> filter_;
+  media::AudioInputDeviceIPC* ipc_;
 
   // Our stream ID on the message filter. Only modified on the IO thread.
   int32 stream_id_;