Remove framemarking RTP extension.

BUG=webrtc:11637

Change-Id: I47f8e22473429c9762956444e27cfbafb201b208
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/176442
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31522}
diff --git a/api/rtp_headers.h b/api/rtp_headers.h
index 163347f..454149c 100644
--- a/api/rtp_headers.h
+++ b/api/rtp_headers.h
@@ -21,10 +21,9 @@
 #include "api/units/timestamp.h"
 #include "api/video/color_space.h"
 #include "api/video/video_content_type.h"
-#include "api/video/video_frame_marking.h"
 #include "api/video/video_rotation.h"
 #include "api/video/video_timing.h"
-#include "common_types.h"  // NOLINT(build/include)
+#include "common_types.h"  // NOLINT (build/include)
 
 namespace webrtc {
 
@@ -143,9 +142,6 @@
   bool has_video_timing;
   VideoSendTiming video_timing;
 
-  bool has_frame_marking;
-  FrameMarking frame_marking;
-
   PlayoutDelay playout_delay = {-1, -1};
 
   // For identification of a stream when ssrc is not signaled. See