Implement video frame acknowledgements in the chromoting protocol.

remoting/host/video_frame_pump.h

Index: remoting/host/video_frame_pump.h
diff --git a/remoting/host/video_frame_pump.h b/remoting/host/video_frame_pump.h
index 2f36d0dd37f2dd48b9fd7f50c250f19bee439076..5bafa3e17fefe6e5af27dac1c39743538d948648 100644
--- a/remoting/host/video_frame_pump.h
+++ b/remoting/host/video_frame_pump.h
@@ -23,6 +23,7 @@ class SingleThreadTaskRunner;
 namespace remoting {
 
 namespace protocol {
+class VideoFeedbackStub;
 class VideoStub;
 }  // namespace protocol
 
@@ -90,6 +91,10 @@ class VideoFramePump : public webrtc::DesktopCapturer::Callback {
   void SetLosslessEncode(bool want_lossless);
   void SetLosslessColor(bool want_lossless);
 
+  protocol::VideoFeedbackStub* video_feedback_stub() {
+    return &capture_scheduler_;
+  }
+
  private:
   // webrtc::DesktopCapturer::Callback interface.
   webrtc::SharedMemory* CreateSharedMemory(size_t size) override;
@@ -103,8 +108,7 @@ class VideoFramePump : public webrtc::DesktopCapturer::Callback {
                         base::TimeTicks timestamp,
                         scoped_ptr<VideoPacket> packet);
 
-  // Callback passed to |video_stub_| for the last packet in each frame, to
-  // rate-limit frame captures to network throughput.
+  // Callback passed to |video_stub_|.
   void OnVideoPacketSent();
 
   // Called by |keep_alive_timer_|.
@@ -113,8 +117,6 @@ class VideoFramePump : public webrtc::DesktopCapturer::Callback {
   // Callback for |video_stub_| called after a keep-alive packet is sent.
   void OnKeepAlivePacketSent();
 
-  base::ThreadChecker thread_checker_;
-
   // Task runner used to run |encoder_|.
   scoped_refptr<base::SingleThreadTaskRunner> encode_task_runner_;
 
@@ -138,6 +140,8 @@ class VideoFramePump : public webrtc::DesktopCapturer::Callback {
   // Number updated by the caller to trace performance.
   int64 latest_event_timestamp_;
 
+  base::ThreadChecker thread_checker_;
+
   base::WeakPtrFactory<VideoFramePump> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoFramePump);