Implement timing frames.

webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h

Index: webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
index d3e72ebd22af9b294d04daa432d5f14e40ad57f4..c0a4bca913e6ce96a1ceaf0098fbb8b34d447e9a 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
+++ b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
@@ -15,6 +15,7 @@
 
 #include "webrtc/api/video/video_content_type.h"
 #include "webrtc/api/video/video_rotation.h"
+#include "webrtc/api/video/video_timing.h"
 #include "webrtc/base/array_view.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 
@@ -126,6 +127,24 @@ class VideoContentTypeExtension {
   static bool Write(uint8_t* data, VideoContentType content_type);
 };
 
+class VideoTimingExtension {
+ public:
+  static constexpr RTPExtensionType kId = kRtpExtensionVideoTiming;
+  static constexpr uint8_t kValueSizeBytes = 12;
+  static constexpr const char* kUri =
+      "http://www.webrtc.org/experiments/rtp-hdrext/video-timing";
+
+  static bool Parse(rtc::ArrayView<const uint8_t> data, VideoTiming* timing);
+  static size_t ValueSize(const VideoTiming&) { return kValueSizeBytes; }
+  static bool Write(uint8_t* data, const VideoTiming& timing);
+
+  static size_t ValueSize(uint16_t time_delta_ms, uint8_t idx) {
+    return kValueSizeBytes;
+  }
+  // Writes only single time delta to position idx.
+  static bool Write(uint8_t* data, uint16_t time_delta_ms, uint8_t idx);
+};
+
 class RtpStreamId {
  public:
   static constexpr RTPExtensionType kId = kRtpExtensionRtpStreamId;