Revert 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 eabde400aae732db1281b12bc9b80b3313f2891b..7957451c2b4db05b3e034dc7f521ba7fc6d28475 100644
--- a/webrtc/video/payload_router.cc
+++ b/webrtc/video/payload_router.cc
@@ -130,7 +130,7 @@
     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_.flags != TimingFrameFlags::kInvalid) {
+  if (encoded_image.timing_.is_timing_frame) {
     rtp_video_header.video_timing.encode_start_delta_ms =
         VideoSendTiming::GetDeltaCappedMs(
             encoded_image.capture_time_ms_,
@@ -143,8 +143,10 @@
     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;