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

content/renderer/pepper/pepper_platform_audio_output_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_AUDIO_OUTPUT_IMPL_H_
 #define CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_AUDIO_OUTPUT_IMPL_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
-#include "content/renderer/media/audio_message_filter.h"
+#include "media/audio/audio_output_ipc.h"
 #include "webkit/plugins/ppapi/plugin_delegate.h"
 
 namespace media{
 class AudioParameters;
 }
 
 namespace base {
 class MessageLoopProxy;
 }
 
 namespace content {
 
 class PepperPlatformAudioOutputImpl
     : public webkit::ppapi::PluginDelegate::PlatformAudioOutput,
-      public AudioMessageFilter::Delegate,
+      public media::AudioOutputIPCDelegate,
       public base::RefCountedThreadSafe<PepperPlatformAudioOutputImpl> {
  public:
   // Factory function, returns NULL on failure. StreamCreated() will be called
   // when the stream is created.
   static PepperPlatformAudioOutputImpl* Create(
       int sample_rate,
       int frames_per_buffer,
       webkit::ppapi::PluginDelegate::PlatformAudioOutputClient* client);
 
   // PlatformAudioOutput implementation (called on main thread).
   virtual bool StartPlayback() OVERRIDE;
   virtual bool StopPlayback() OVERRIDE;
   virtual void ShutDown() OVERRIDE;
 
-  // AudioMessageFilter::Delegate.
-  virtual void OnStateChanged(AudioStreamState state) OVERRIDE;
+  // media::AudioOutputIPCDelegate implementation.
+  virtual void OnStateChanged(
+      media::AudioOutputIPCDelegate::State state) OVERRIDE;
   virtual void OnStreamCreated(base::SharedMemoryHandle handle,
                                base::SyncSocket::Handle socket_handle,
-                               uint32 length) OVERRIDE;
+                               int length) OVERRIDE;
+  virtual void OnIPCClosed() OVERRIDE;
 
  protected:
   virtual ~PepperPlatformAudioOutputImpl();
 
  private:
   friend class base::RefCountedThreadSafe<PepperPlatformAudioOutputImpl>;
 
   PepperPlatformAudioOutputImpl();
 
   bool Initialize(
       int sample_rate,
       int frames_per_buffer,
       webkit::ppapi::PluginDelegate::PlatformAudioOutputClient* client);
 
   // I/O thread backends to above functions.
   void InitializeOnIOThread(const media::AudioParameters& params);
   void StartPlaybackOnIOThread();
   void StopPlaybackOnIOThread();
   void ShutDownOnIOThread();
 
   // The client to notify when the stream is created. THIS MUST ONLY BE
   // ACCESSED ON THE MAIN THREAD.
   webkit::ppapi::PluginDelegate::PlatformAudioOutputClient* client_;
 
-  // MessageFilter used to send/receive IPC. THIS MUST ONLY BE ACCESSED ON THE
+  // Used to send/receive IPC. THIS MUST ONLY BE ACCESSED ON THE
   // I/O thread except to send messages and get the message loop.
-  scoped_refptr<AudioMessageFilter> filter_;
+  media::AudioOutputIPC* ipc_;
 
   // Our ID on the MessageFilter. THIS MUST ONLY BE ACCESSED ON THE I/O THREAD
   // or else you could race with the initialize function which sets it.
   int32 stream_id_;
 
   base::MessageLoopProxy* main_message_loop_proxy_;
 
   DISALLOW_COPY_AND_ASSIGN(PepperPlatformAudioOutputImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_AUDIO_OUTPUT_IMPL_H_