Add cricket::VideoFrame::frame_id() and set it to RTP timestamp.

webrtc/media/base/videobroadcaster.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 37 matching lines @@
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   rtc::CritScope cs(&sinks_and_wants_lock_);
   return current_wants_;
 }
 
 void VideoBroadcaster::OnFrame(const cricket::VideoFrame& frame) {
   rtc::CritScope cs(&sinks_and_wants_lock_);
   for (auto& sink_pair : sink_pairs()) {
     if (sink_pair.wants.black_frames) {
       sink_pair.sink->OnFrame(cricket::WebRtcVideoFrame(
-          GetBlackFrameBuffer(frame.width(), frame.height()),
-          frame.rotation(), frame.timestamp_us()));
+          GetBlackFrameBuffer(frame.width(), frame.height()), frame.rotation(),
+          frame.timestamp_us(), frame.transport_frame_id()));
     } else {
       sink_pair.sink->OnFrame(frame);
     }
   }
 }
 
 void VideoBroadcaster::UpdateWants() {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
 
   VideoSinkWants wants;
@@ skipping 32 matching lines @@
     rtc::scoped_refptr<webrtc::I420Buffer> buffer =
         new RefCountedObject<webrtc::I420Buffer>(width, height);
     buffer->SetToBlack();
     black_frame_buffer_ = buffer;
   }
 
   return black_frame_buffer_;
 }
 
 }  // namespace rtc