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

webrtc/p2p/base/transportcontroller.cc

 /*
  *  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 555 matching lines @@
 }
 
 void TransportController::OnChannelWritableState_n(
     rtc::PacketTransportInterface* transport) {
   RTC_DCHECK(network_thread_->IsCurrent());
   LOG(LS_INFO) << " TransportChannel " << transport->debug_name()
                << " writability changed to " << transport->writable() << ".";
   UpdateAggregateStates_n();
 }
 
-void TransportController::OnChannelReceivingState_n(TransportChannel* channel) {
+void TransportController::OnChannelReceivingState_n(
+    rtc::PacketTransportInterface* transport) {
   RTC_DCHECK(network_thread_->IsCurrent());
   UpdateAggregateStates_n();
 }
 
 void TransportController::OnChannelGatheringState_n(
     TransportChannelImpl* channel) {
   RTC_DCHECK(network_thread_->IsCurrent());
   UpdateAggregateStates_n();
 }
 
@@ skipping 120 matching lines @@
 
 void TransportController::SetMetricsObserver(
     webrtc::MetricsObserverInterface* metrics_observer) {
   metrics_observer_ = metrics_observer;
   for (auto channel : channels_) {
     channel->SetMetricsObserver(metrics_observer);
   }
 }
 
 }  // namespace cricket