Implement video frame acknowledgements in the chromoting protocol.

remoting/protocol/client_video_dispatcher.cc

Index: remoting/protocol/client_video_dispatcher.cc
diff --git a/remoting/protocol/client_video_dispatcher.cc b/remoting/protocol/client_video_dispatcher.cc
index 287bba329cab9ee428d4a87b2a5f850499f27910..0ad990c34bd8c28ecbb3b043f3a443100ee9e645 100644
--- a/remoting/protocol/client_video_dispatcher.cc
+++ b/remoting/protocol/client_video_dispatcher.cc
@@ -8,6 +8,8 @@
 #include "net/socket/stream_socket.h"
 #include "remoting/base/constants.h"
 #include "remoting/proto/video.pb.h"
+#include "remoting/protocol/errors.h"
+#include "remoting/protocol/message_serialization.h"
 #include "remoting/protocol/video_stub.h"
 
 namespace remoting {
@@ -15,13 +17,52 @@ namespace protocol {
 
 ClientVideoDispatcher::ClientVideoDispatcher(VideoStub* video_stub)
     : ChannelDispatcherBase(kVideoChannelName),
-      parser_(base::Bind(&VideoStub::ProcessVideoPacket,
-                         base::Unretained(video_stub)),
+      video_stub_(video_stub),
+      parser_(base::Bind(&ClientVideoDispatcher::ProcessVideoPacket,
+                         base::Unretained(this)),
               reader()) {
 }
 
 ClientVideoDispatcher::~ClientVideoDispatcher() {
 }
 
+void ClientVideoDispatcher::ProcessVideoPacket(
+    scoped_ptr<VideoPacket> video_packet,
+    const base::Closure& done) {
+  base::TimeTicks now = base::TimeTicks::Now();
+
+  int frame_id = video_packet->frame_id();
+  video_stub_->ProcessVideoPacket(
+      video_packet.Pass(),
+      base::Bind(&ClientVideoDispatcher::OnPacketProgress,
+                 base::Unretained(this), frame_id,
+                 reader()->last_message_read_duration(), now, done));
+}
+
+void ClientVideoDispatcher::OnPacketProgress(
+    int frame_id,
+    base::TimeDelta time_to_receive,
+    base::TimeTicks received_time,
+    const base::Closure& done,
+    VideoStub::PacketProgress packet_progress) {
+  // Only interested in DONE notification.
+  if (packet_progress != VideoStub::PacketProgress::DONE)
+    return;
+
+  done.Run();
+
+  // Don't send Ack message if the host doesn't support it.
+  if (channel_config().version <= kVideoStreamVersionNoAck)
+    return;
+
+  // Send VideoAck.
+  VideoAck ack_message;
+  ack_message.set_frame_id(frame_id);
+  ack_message.set_time_to_receive_us(time_to_receive.InMicroseconds());
+  ack_message.set_rendering_delay_us(
+      (base::TimeTicks::Now() - received_time).InMicroseconds());
+  writer()->Write(SerializeAndFrameMessage(ack_message), base::Closure());
+}
+
 }  // namespace protocol
 }  // namespace remoting