Added JsonMessage to the control channel.

remoting/protocol/host_stub.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.
 
 // Interface of a host that receives commands from a Chromoting client.
 //
 // This interface handles control messages defined in control.proto.
 
 #ifndef REMOTING_PROTOCOL_HOST_STUB_H_
 #define REMOTING_PROTOCOL_HOST_STUB_H_
 
 #include "base/basictypes.h"
 
 namespace remoting {
 namespace protocol {
 
 class AudioControl;
 class Capabilities;
 class ClientResolution;
+class ExtensionMessage;
 class PairingResponse;
 class PairingRequest;
 class VideoControl;
 
 class HostStub {
  public:
   HostStub() {}
 
   // Notification of the client dimensions and pixel density.
   // This may be used to resize the host display to match the client area.
   virtual void NotifyClientResolution(const ClientResolution& resolution) = 0;
 
   // Configures video update properties. Currently only pausing & resuming the
   // video channel is supported.
   virtual void ControlVideo(const VideoControl& video_control) = 0;
 
   // Configures audio properties. Currently only pausing & resuming the audio
   // channel is supported.
   virtual void ControlAudio(const AudioControl& audio_control) = 0;
 
   // Passes the set of capabilities supported by the client to the host.
   virtual void SetCapabilities(const Capabilities& capabilities) = 0;
 
   // Requests pairing between the host and client for PIN-less authentication.
   virtual void RequestPairing(const PairingRequest& pairing_request) = 0;
 
+  // Deliver an extension message from the client to the host.
+  virtual void DeliverClientMessage(const ExtensionMessage& message) = 0;
+
  protected:
   virtual ~HostStub() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(HostStub);
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_HOST_STUB_H_