Implement InputStub in the host side for chromoting

remoting/host/chromoting_host_context.h

Index: remoting/host/chromoting_host_context.h
diff --git a/remoting/host/chromoting_host_context.h b/remoting/host/chromoting_host_context.h
index 713afb81510fec26fdbf6bef0d216d32010adc92..96b63b3890415516880f6fdd662fb8c85d80bdbf 100644
--- a/remoting/host/chromoting_host_context.h
+++ b/remoting/host/chromoting_host_context.h
@@ -28,8 +28,10 @@ class ChromotingHostContext {
   virtual void Stop();
 
   virtual JingleThread* jingle_thread();
+
+  // TODO(hclam): Change these all to MessageLoopProxy.
   virtual MessageLoop* main_message_loop();
-  virtual MessageLoop* capture_message_loop();
+  virtual scoped_refptr<base::MessageLoopProxy> capture_message_loop_proxy();

[awong, 2010/11/12 01:40:10]

The more I think about this, more I don't really see a need to use the proxy. 
If nothing else, it makes all these calls ugly cause you have to say _proxy()
everywhere.  Our destruction is structured well enough that I don't think that
this will save us anything in practicality.

   virtual MessageLoop* encode_message_loop();
 
  private: