Revert of Remove the IceTransportInternal2.

webrtc/p2p/base/icetransportinternal.h

 /*
  *  Copyright 2016 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_P2P_BASE_ICETRANSPORTINTERNAL_H_
 #define WEBRTC_P2P_BASE_ICETRANSPORTINTERNAL_H_
 
 #include <string>
 
 #include "webrtc/p2p/base/candidate.h"
 #include "webrtc/p2p/base/candidatepairinterface.h"
 #include "webrtc/p2p/base/jseptransport.h"
 #include "webrtc/p2p/base/packettransportinterface.h"
 #include "webrtc/p2p/base/transportdescription.h"
 
 namespace webrtc {
 class MetricsObserverInterface;
 }
 
 namespace cricket {
 
+class IceTransportInternal;
+typedef IceTransportInternal IceTransportInternal2;
+
 // TODO(zhihuang): replace it with PeerConnectionInterface::IceConnectionState.
 enum class IceTransportState {
   STATE_INIT,
   STATE_CONNECTING,  // Will enter this state once a connection is created
   STATE_COMPLETED,
   STATE_FAILED
 };
 
 // TODO(zhihuang): Remove this once it's no longer used in
 // remoting/protocol/libjingle_transport_factory.cc
@@ skipping 97 matching lines @@
 
   // Debugging description of this transport.
   const std::string debug_name() const override {
     return transport_name() + " " + std::to_string(component());
   }
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_ICETRANSPORTINTERNAL_H_