Move responsibility for RTP header extensions on video receive.

webrtc/pc/mediacontroller.h

 /*
  *  Copyright 2015 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_PC_MEDIACONTROLLER_H_
 #define WEBRTC_PC_MEDIACONTROLLER_H_
 
 #include "webrtc/base/thread.h"
+#include "webrtc/config.h"
 
 namespace cricket {
 class ChannelManager;
 struct MediaConfig;
 }  // namespace cricket
 
 namespace webrtc {
 class Call;
 class VoiceEngine;
 class RtcEventLog;
 
 // The MediaController currently owns shared state between media channels.
 // Abstract interface is defined here such that it can be faked/mocked for
 // tests, but no other real reason.
 class MediaControllerInterface {
  public:
   // Will never return nullptr.
   static MediaControllerInterface* Create(
       const cricket::MediaConfig& config,
       rtc::Thread* worker_thread,
       cricket::ChannelManager* channel_manager,
       webrtc::RtcEventLog* event_log);
 
   virtual ~MediaControllerInterface() {}
   virtual void Close() = 0;
   virtual webrtc::Call* call_w() = 0;
   virtual cricket::ChannelManager* channel_manager() const = 0;
   virtual const cricket::MediaConfig& config() const = 0;
+  // Proxy for Call (extensions may change mid-call).
+  // TODO(nisse): Should belong to RtpTransportController.
+  virtual void SetVideoReceiveRtpHeaderExtensions(
+      const std::vector<RtpExtension>& extensions) = 0;

[pthatcher1, 2017/04/29 00:25:18]

This shouldn't be at the per-MediaController level.  There will be many
RtpTransports per MediaCotnroller, and each one needs to support independent
extensions.

 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_PC_MEDIACONTROLLER_H_