Implement video frame acknowledgements in the chromoting protocol.

remoting/proto/video.proto

 // 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.
 
 // Protocol for video messages.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
@@ skipping 48 matching lines @@
   // starting to capture this video frame.
   optional int64 latest_event_timestamp = 9;
 
   repeated Rect desktop_shape_rects = 10;
 
   // True when |desktop_shape_rects| should be used.
   optional bool use_desktop_shape = 11;
 
   // Optional frame timestamp. Used in tests to estimate frame latency.
   optional int64 timestamp = 12;
+
+  optional int32 frame_id = 13;
 }
+
+message VideoAck {
+  // Frame ID.
+  optional int32 frame_id = 1;
+
+  // Time in microseconds it took to receive this frame from the beginning to
+  // the end.

[Wez, 2015/01/21 01:35:38]

nit: to receive the VideoPacket.

Also consider noting that for small VideoPackets this can be zero.

[Sergey Ulanov, 2015/01/29 01:33:28]

Done.

+  optional int32 time_to_receive_us = 2;
+
+  // Time in microseconds it took to render the frame.
+  optional int32 rendering_delay_us = 3;
+}