Build WebRTC with data channel only.

webrtc/sdk/objc/Framework/Classes/RTCVideoRendererAdapter.mm

 /*
  *  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.
  */
 
 #import "RTCVideoRendererAdapter+Private.h"
 
 #import "RTCVideoFrame+Private.h"
 
 #include <memory>
 
+#include "webrtc/base/timeutils.h"
+
 namespace webrtc {
 
 class VideoRendererAdapter
     : public rtc::VideoSinkInterface<webrtc::VideoFrame> {
  public:
   VideoRendererAdapter(RTCVideoRendererAdapter* adapter) {
     adapter_ = adapter;
     size_ = CGSizeZero;
   }
 
@@ skipping 34 matching lines @@
     _adapter.reset(new webrtc::VideoRendererAdapter(self));
   }
   return self;
 }
 
 - (rtc::VideoSinkInterface<webrtc::VideoFrame> *)nativeVideoRenderer {
   return _adapter.get();
 }
 
 @end