Implement video frame acknowledgements in the chromoting protocol.

remoting/protocol/connection_to_client.h

Index: remoting/protocol/connection_to_client.h
diff --git a/remoting/protocol/connection_to_client.h b/remoting/protocol/connection_to_client.h
index 2cdd60be0c7e4f96d0e4c37a784061be2878a687..43c0b1afa0ccc793ff5a98261366188a84054200 100644
--- a/remoting/protocol/connection_to_client.h
+++ b/remoting/protocol/connection_to_client.h
@@ -25,6 +25,7 @@ class HostEventDispatcher;
 class HostStub;
 class HostVideoDispatcher;
 class InputStub;
+class VideoFeedbackStub;
 class VideoStub;
 
 // This class represents a remote viewer connection to the chromoting
@@ -98,6 +99,10 @@ class ConnectionToClient : public base::NonThreadSafe,
   virtual void set_host_stub(HostStub* host_stub);
   virtual void set_input_stub(InputStub* input_stub);
 
+  // Sets video feedback stub. Can be called at any time after connection is
+  // authenticated.
+  virtual void set_video_feedback_stub(VideoFeedbackStub* video_feedback_stub);
+
   // Session::EventHandler interface.
   void OnSessionStateChange(Session::State state) override;
   void OnSessionRouteChange(const std::string& channel_name,