Support building WebRTC without audio and video for IOS

webrtc/sdk/objc/Framework/Classes/PeerConnection/RTCPeerConnectionFactory+Private.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.
  */
 
 #import "WebRTC/RTCPeerConnectionFactory.h"
 
 #include "webrtc/api/peerconnectioninterface.h"
 #include "webrtc/base/scoped_ref_ptr.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
-@interface RTCPeerConnectionFactory ()
+@interface RTCPeerConnectionFactory () {
+  std::unique_ptr<rtc::Thread> _networkThread;

[tkchin_webrtc, 2017/06/20 21:51:24]

style: don't declare ivars in @interface decls

If you need them shared, declare them as properties instead

+  std::unique_ptr<rtc::Thread> _workerThread;
+  std::unique_ptr<rtc::Thread> _signalingThread;
+  BOOL _hasStartedAecDump;
+  rtc::scoped_refptr<webrtc::PeerConnectionFactoryInterface> _nativeFactory;
+}
 
 /**
  * PeerConnectionFactoryInterface created and held by this
  * RTCPeerConnectionFactory object. This is needed to pass to the underlying
  * C++ APIs.
  */
 @property(nonatomic, readonly)
     rtc::scoped_refptr<webrtc::PeerConnectionFactoryInterface> nativeFactory;
 
 @end
 
 NS_ASSUME_NONNULL_END