Reland of Add a flags field to video timing extension.

webrtc/video/payload_router.cc

Index: webrtc/video/payload_router.cc
diff --git a/webrtc/video/payload_router.cc b/webrtc/video/payload_router.cc
index 7957451c2b4db05b3e034dc7f521ba7fc6d28475..eabde400aae732db1281b12bc9b80b3313f2891b 100644
--- a/webrtc/video/payload_router.cc
+++ b/webrtc/video/payload_router.cc
@@ -130,7 +130,7 @@ EncodedImageCallback::Result PayloadRouter::OnEncodedImage(
     CopyCodecSpecific(codec_specific_info, &rtp_video_header);
   rtp_video_header.rotation = encoded_image.rotation_;
   rtp_video_header.content_type = encoded_image.content_type_;
-  if (encoded_image.timing_.is_timing_frame) {
+  if (encoded_image.timing_.flags != TimingFrameFlags::kInvalid) {
     rtp_video_header.video_timing.encode_start_delta_ms =
         VideoSendTiming::GetDeltaCappedMs(
             encoded_image.capture_time_ms_,
@@ -143,10 +143,8 @@ EncodedImageCallback::Result PayloadRouter::OnEncodedImage(
     rtp_video_header.video_timing.pacer_exit_delta_ms = 0;
     rtp_video_header.video_timing.network_timstamp_delta_ms = 0;
     rtp_video_header.video_timing.network2_timstamp_delta_ms = 0;
-    rtp_video_header.video_timing.is_timing_frame = true;
-  } else {
-    rtp_video_header.video_timing.is_timing_frame = false;
   }
+  rtp_video_header.video_timing.flags = encoded_image.timing_.flags;
   rtp_video_header.playout_delay = encoded_image.playout_delay_;
 
   int stream_index = rtp_video_header.simulcastIdx;