Create //webrtc/api:libjingle_peerconnection_api + refactorings.

webrtc/sdk/objc/Framework/Classes/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/peerconnectionfactory.h"
+#include "webrtc/api/peerconnectioninterface.h"
 #include "webrtc/base/scoped_ref_ptr.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
 @interface RTCPeerConnectionFactory ()
 
 /**
  * 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