Move IPC::MessageFilter and router to a separate file

content/renderer/media/android/renderer_demuxer_android.h

Index: content/renderer/media/android/renderer_demuxer_android.h
diff --git a/content/renderer/media/android/renderer_demuxer_android.h b/content/renderer/media/android/renderer_demuxer_android.h
index c6538a1b2cb6c0ba589c29618c11f0cfe9d85d79..b1dac131ab0f22a386e9f76841838483f0b12d51 100644
--- a/content/renderer/media/android/renderer_demuxer_android.h
+++ b/content/renderer/media/android/renderer_demuxer_android.h
@@ -7,9 +7,13 @@
 
 #include "base/atomic_sequence_num.h"
 #include "base/id_map.h"
-#include "ipc/ipc_channel_proxy.h"
+#include "ipc/message_filter.h"
 #include "media/base/android/demuxer_stream_player_params.h"
 
+namespace base {
+class MessageLoopProxy;
+}
+
 namespace content {
 
 class MediaSourceDelegate;
@@ -19,7 +23,7 @@ class ThreadSafeSender;
 // media::DemuxerAndroid.
 //
 // Refer to BrowserDemuxerAndroid for the browser process half.
-class RendererDemuxerAndroid : public IPC::ChannelProxy::MessageFilter {
+class RendererDemuxerAndroid : public IPC::MessageFilter {
  public:
   RendererDemuxerAndroid();
 
@@ -39,7 +43,7 @@ class RendererDemuxerAndroid : public IPC::ChannelProxy::MessageFilter {
   // Must be called on media thread.
   void RemoveDelegate(int demuxer_client_id);
 
-  // IPC::ChannelProxy::MessageFilter overrides.
+  // IPC::MessageFilter overrides.
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
   // media::DemuxerAndroidClient "implementation".