Add write support for the RtpStreamId and RepairedRtpStreamId header extensions.

webrtc/modules/rtp_rtcp/source/rtp_packet.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_PACKET_H_
@@ skipping 165 matching lines @@
 template <typename Extension, typename... Values>
 bool Packet::GetExtension(Values... values) const {
   auto raw = FindExtension(Extension::kId);
   if (raw.empty())
     return false;
   return Extension::Parse(raw, values...);
 }
 
 template <typename Extension, typename... Values>
 bool Packet::SetExtension(Values... values) {
-  auto buffer = AllocateExtension(Extension::kId, Extension::kValueSizeBytes);
+  auto buffer = AllocateExtension(Extension::kId,
+                                  Extension::ValueSize(values...));
   if (buffer.empty())
     return false;
   return Extension::Write(buffer.data(), values...);
 }
 
 template <typename Extension>
 bool Packet::ReserveExtension() {
   auto buffer = AllocateExtension(Extension::kId, Extension::kValueSizeBytes);
   if (buffer.empty())
     return false;
   memset(buffer.data(), 0, Extension::kValueSizeBytes);
   return true;
 }
 }  // namespace rtp
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_PACKET_H_