Use MessageLoopProxy for network message loop.

remoting/protocol/host_control_sender.h

Index: remoting/protocol/host_control_sender.h
diff --git a/remoting/protocol/host_control_sender.h b/remoting/protocol/host_control_sender.h
index b1b88de16d393d4537be1afc652869807b8f19b9..c1425daf786f48fc305f4e2847aef0ed8c4cf895 100644
--- a/remoting/protocol/host_control_sender.h
+++ b/remoting/protocol/host_control_sender.h
@@ -18,6 +18,10 @@
 
 class Task;
 
+namespace base {
+class MessageLoopProxy;
+}  // namespace base
+
 namespace net {
 class Socket;
 }  // namespace net
@@ -32,7 +36,8 @@ class BufferedSocketWriter;
 // other thread.
 class HostControlSender : public HostStub {
  public:
-  explicit HostControlSender(net::Socket* socket);
+  explicit HostControlSender(base::MessageLoopProxy* message_loop,
+                             net::Socket* socket);
   virtual ~HostControlSender();
 
   virtual void BeginSessionRequest(