Create //webrtc/api:libjingle_peerconnection_api + refactorings.

webrtc/pc/ortcfactory.h

 /*
  *  Copyright 2017 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_ORTCFACTORY_H_
-#define WEBRTC_API_ORTCFACTORY_H_
+#ifndef WEBRTC_PC_ORTCFACTORY_H_
+#define WEBRTC_PC_ORTCFACTORY_H_
 
 #include <memory>
 
 #include "webrtc/api/ortcfactoryinterface.h"
 #include "webrtc/base/constructormagic.h"
 
 namespace webrtc {
 
 // Implementation of OrtcFactoryInterface.
 //
@@ skipping 31 matching lines @@
   PROXY_SIGNALING_THREAD_DESTRUCTOR()
   PROXY_METHOD3(std::unique_ptr<UdpTransportInterface>,
                 CreateUdpTransport,
                 int,
                 uint16_t,
                 uint16_t)
 END_PROXY_MAP()
 
 }  // namespace webrtc
 
-#endif  // WEBRTC_API_ORTCFACTORY_H_
+#endif  // WEBRTC_PC_ORTCFACTORY_H_