Don't depend on MessageLoopProxy in remoting protocol code.

remoting/protocol/video_writer.h

Index: remoting/protocol/video_writer.h
diff --git a/remoting/protocol/video_writer.h b/remoting/protocol/video_writer.h
index 67d3a7b75a488af6a485608c196a3a8a71805092..3d125a3ba6524a369541276d13471801e257af3b 100644
--- a/remoting/protocol/video_writer.h
+++ b/remoting/protocol/video_writer.h
@@ -13,10 +13,6 @@
 #include "base/callback.h"
 #include "remoting/protocol/video_stub.h"
 
-namespace base {
-class MessageLoopProxy;
-}  // namespace base
-
 namespace remoting {
 namespace protocol {
 
@@ -31,8 +27,7 @@ class VideoWriter : public VideoStub {
   // parameter is set to true on success.
   typedef base::Callback<void(bool)> InitializedCallback;
 
-  static VideoWriter* Create(base::MessageLoopProxy* message_loop,
-                             const SessionConfig& config);
+  static VideoWriter* Create(const SessionConfig& config);
 
   // Initializes the writer.
   virtual void Init(Session* session, const InitializedCallback& callback) = 0;