Report timing frames info in GetStats.

webrtc/media/base/mediachannel.h

Index: webrtc/media/base/mediachannel.h
diff --git a/webrtc/media/base/mediachannel.h b/webrtc/media/base/mediachannel.h
index 816dfd18fc987a3995396e4afa31839f69a3eac8..bf9ef7d164abed59e36394e7d24e478a41be3e35 100644
--- a/webrtc/media/base/mediachannel.h
+++ b/webrtc/media/base/mediachannel.h
@@ -17,6 +17,7 @@
 
 #include "webrtc/api/rtpparameters.h"
 #include "webrtc/api/rtpreceiverinterface.h"
+#include "webrtc/api/video/video_timing.h"
 #include "webrtc/base/basictypes.h"
 #include "webrtc/base/buffer.h"
 #include "webrtc/base/copyonwritebuffer.h"
@@ -747,8 +748,8 @@ struct VideoReceiverInfo : public MediaReceiverInfo {
         render_delay_ms(0),
         target_delay_ms(0),
         current_delay_ms(0),
-        capture_start_ntp_time_ms(-1) {
-  }
+        capture_start_ntp_time_ms(-1),
+        timing_frame_info() {}
 
   std::vector<SsrcGroup> ssrc_groups;
   // TODO(hbos): Move this to |VideoMediaInfo::receive_codecs|?
@@ -793,6 +794,10 @@ struct VideoReceiverInfo : public MediaReceiverInfo {
 
   // Estimated capture start time in NTP time in ms.
   int64_t capture_start_ntp_time_ms;
+
+  // Timing frame info: all important timestamps for a full lifetime of a
+  // single 'timing frame'.
+  webrtc::TimingFrameInfo timing_frame_info;

[hbos, 2017/06/27 14:08:31]

Should this be rtc::Optional<webrtc::TimingFrameInfo>?

What is required in order to obtain this metric? That an extension header is
present? No need to have both sending and receiving streams?

[ilnik, 2017/06/27 15:23:56]

Now it's Optional<>. This info will be reported by design only if extension
header is present only for frames for which we know full information.

 };
 
 struct DataSenderInfo : public MediaSenderInfo {