Revert of Make P2PTransportChannel inherit from IceTransportInternal.

webrtc/p2p/base/udptransportchannel.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.
  */
 
@@ skipping 17 matching lines @@
 
 namespace cricket {
 
 class UdpTransportChannel : public rtc::PacketTransportInterface {
  public:
   enum class State { INIT, CONNECTING, CONNECTED, FAILED };
   explicit UdpTransportChannel(const std::string& transport_name);
   UdpTransportChannel(const std::string& transport_name, rtc::SocketServer* ss);
   ~UdpTransportChannel();
 
-  std::string debug_name() const override { return transport_name_; }
+  const std::string debug_name() const override { return transport_name_; }
 
   bool receiving() const override {
     // TODO(johan): Implement method and signal.
     return true;
   }
 
   bool writable() const override;
 
   int SendPacket(const char* data,
                  size_t len,
@@ skipping 38 matching lines @@
   State state_ = State::INIT;
   int send_error_ = 0;
   std::unique_ptr<rtc::AsyncPacketSocket> socket_;
   rtc::Optional<rtc::SocketAddress> local_parameters_;
   rtc::Optional<rtc::SocketAddress> remote_parameters_;
   rtc::ThreadChecker network_thread_checker_;
 };
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_UDPTRANSPORTCHANNEL_H_