Let receiving() and SignalReceivingState be part of rtc::PacketTransportInterface.

webrtc/p2p/base/transportcontroller.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.
  */
 
@@ skipping 188 matching lines @@
   void MaybeStartGathering_n();
   bool AddRemoteCandidates_n(const std::string& transport_name,
                              const Candidates& candidates,
                              std::string* err);
   bool RemoveRemoteCandidates_n(const Candidates& candidates, std::string* err);
   bool ReadyForRemoteCandidates_n(const std::string& transport_name);
   bool GetStats_n(const std::string& transport_name, TransportStats* stats);
 
   // Handlers for signals from Transport.
   void OnChannelWritableState_n(rtc::PacketTransportInterface* transport);
-  void OnChannelReceivingState_n(TransportChannel* channel);
+  void OnChannelReceivingState_n(rtc::PacketTransportInterface* transport);
   void OnChannelGatheringState_n(TransportChannelImpl* channel);
   void OnChannelCandidateGathered_n(TransportChannelImpl* channel,
                                     const Candidate& candidate);
   void OnChannelCandidatesRemoved(const Candidates& candidates);
   void OnChannelCandidatesRemoved_n(TransportChannelImpl* channel,
                                     const Candidates& candidates);
   void OnChannelRoleConflict_n(TransportChannelImpl* channel);
   void OnChannelStateChanged_n(TransportChannelImpl* channel);
 
   void UpdateAggregateStates_n();
@@ skipping 24 matching lines @@
   rtc::AsyncInvoker invoker_;
   // True if QUIC is used instead of DTLS.
   bool quic_ = false;
 
   webrtc::MetricsObserverInterface* metrics_observer_ = nullptr;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_TRANSPORTCONTROLLER_H_