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

webrtc/p2p/base/transportchannel.h

 /*
  *  Copyright 2004 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 58 matching lines @@
 
   const std::string& transport_name() const { return transport_name_; }
   int component() const { return component_; }
   const std::string debug_name() const override {
     return transport_name() + " " + std::to_string(component());
   }
 
   // Returns the states of this channel.  Each time one of these states changes,
   // a signal is raised.  These states are aggregated by the TransportManager.
   bool writable() const override { return writable_; }
-  bool receiving() const { return receiving_; }
+  bool receiving() const override { return receiving_; }
   DtlsTransportState dtls_state() const { return dtls_state_; }
-  sigslot::signal1<TransportChannel*> SignalReceivingState;
   // Emitted whenever DTLS-SRTP is setup which will require setting up a new
   // SRTP context.
   sigslot::signal2<TransportChannel*, DtlsTransportState> SignalDtlsState;
 
   // Returns the current stats for this connection.
   virtual bool GetStats(ConnectionInfos* infos) = 0;
 
   // Is DTLS active?
   virtual bool IsDtlsActive() const = 0;
 
@@ skipping 70 matching lines @@
   bool writable_;
   bool receiving_;
   DtlsTransportState dtls_state_ = DTLS_TRANSPORT_NEW;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(TransportChannel);
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_TRANSPORTCHANNEL_H_