Introduce struct MediaConfig, with construction-time settings.

webrtc/api/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_API_MEDIACONTROLLER_H_
 #define WEBRTC_API_MEDIACONTROLLER_H_
 
 #include "webrtc/base/thread.h"
 
 namespace cricket {
 class ChannelManager;
+struct MediaConfig;
 }  // namespace cricket
 
 namespace webrtc {
 class Call;
 class VoiceEngine;
 
 // The MediaController currently owns shared state between media channels, but
 // in the future will create and own RtpSenders and RtpReceivers.
 class MediaControllerInterface {
  public:
   static MediaControllerInterface* Create(
+      const cricket::MediaConfig& config,
       rtc::Thread* worker_thread,
       cricket::ChannelManager* channel_manager);
 
   virtual ~MediaControllerInterface() {}
   virtual webrtc::Call* call_w() = 0;
   virtual cricket::ChannelManager* channel_manager() const = 0;
+  virtual const cricket::MediaConfig& config() const = 0;
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_MEDIACONTROLLER_H_