Introduce struct MediaConfig, with construction-time settings.

webrtc/api/fakemediacontroller.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_FAKEMEDIACONTROLLER_H_
 #define WEBRTC_API_FAKEMEDIACONTROLLER_H_
 
 #include "webrtc/api/mediacontroller.h"
 #include "webrtc/base/checks.h"
+#include "webrtc/media/base/mediachannel.h"
 
 namespace cricket {
 
 class FakeMediaController : public webrtc::MediaControllerInterface {
  public:
   explicit FakeMediaController(cricket::ChannelManager* channel_manager,
                                webrtc::Call* call)
       : channel_manager_(channel_manager), call_(call) {
     RTC_DCHECK(nullptr != channel_manager_);
     RTC_DCHECK(nullptr != call_);
   }
   ~FakeMediaController() override {}
   webrtc::Call* call_w() override { return call_; }
   cricket::ChannelManager* channel_manager() const override {
     return channel_manager_;
   }
+  const MediaConfig& config() const override { return media_config_; }
 
  private:
+  const MediaConfig media_config_ = MediaConfig();
   cricket::ChannelManager* channel_manager_;
   webrtc::Call* call_;
 };
 }  // namespace cricket
 #endif  // WEBRTC_API_FAKEMEDIACONTROLLER_H_