Fixing scenario where track is rejected and later un-rejected.

talk/app/webrtc/peerconnection.cc

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 596 matching lines @@
     return;
   }
   // Update stats here so that we have the most recent stats for tracks and
   // streams that might be removed by updating the session description.
   stats_->UpdateStats(kStatsOutputLevelStandard);
   std::string error;
   if (!session_->SetLocalDescription(desc, &error)) {
     PostSetSessionDescriptionFailure(observer, error);
     return;
   }
+
+  // This is necessary because an audio/video channel may have been previously
+  // destroyed by removing it from the remote description, which would NOT
+  // destroy the local handler. So upon receiving a new local description,
+  // we may need to tell that local track handler to connect the capturer
+  // to the now re-created audio/video channel.
+  stream_handler_container_->RestartAllLocalTracks();
+
   SetSessionDescriptionMsg* msg =  new SetSessionDescriptionMsg(observer);
   signaling_thread()->Post(this, MSG_SET_SESSIONDESCRIPTION_SUCCESS, msg);
 }
 
 void PeerConnection::SetRemoteDescription(
     SetSessionDescriptionObserver* observer,
     SessionDescriptionInterface* desc) {
   if (!VERIFY(observer != NULL)) {
     LOG(LS_ERROR) << "SetRemoteDescription - observer is NULL.";
     return;
   }
   if (!desc) {
     PostSetSessionDescriptionFailure(observer, "SessionDescription is NULL.");
     return;
   }
   // Update stats here so that we have the most recent stats for tracks and
   // streams that might be removed by updating the session description.
   stats_->UpdateStats(kStatsOutputLevelStandard);
   std::string error;
   if (!session_->SetRemoteDescription(desc, &error)) {
     PostSetSessionDescriptionFailure(observer, error);
     return;
   }
+
+  // This is necessary because an audio/video channel may have been previously
+  // destroyed by removing it from the local description, which would NOT
+  // destroy the remote handler. So upon receiving a new remote description,
+  // we may need to tell that remote track handler to connect the renderer
+  // to the now re-created audio/video channel.
+  stream_handler_container_->RestartAllRemoteTracks();
+
   SetSessionDescriptionMsg* msg  = new SetSessionDescriptionMsg(observer);
   signaling_thread()->Post(this, MSG_SET_SESSIONDESCRIPTION_SUCCESS, msg);
 }
 
 void PeerConnection::PostSetSessionDescriptionFailure(
     SetSessionDescriptionObserver* observer,
     const std::string& error) {
   SetSessionDescriptionMsg* msg  = new SetSessionDescriptionMsg(observer);
   msg->error = error;
   signaling_thread()->Post(this, MSG_SET_SESSIONDESCRIPTION_FAILED, msg);
@@ skipping 245 matching lines @@
     if (ice_gathering_state_ != kIceGatheringComplete) {
       ice_gathering_state_ = kIceGatheringComplete;
       observer_->OnIceGatheringChange(ice_gathering_state_);
     }
   }
   observer_->OnSignalingChange(signaling_state_);
   observer_->OnStateChange(PeerConnectionObserver::kSignalingState);
 }
 
 }  // namespace webrtc