Removing assert error when we fail to create a connection for a ping from an unknown address

webrtc/p2p/base/p2ptransportchannel.cc

 /*
  *  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 630 matching lines @@
       port->SendBindingErrorResponse(stun_msg, address,
                                      STUN_ERROR_SERVER_ERROR,
                                      STUN_ERROR_REASON_SERVER_ERROR);
       return;
     }
   }
 
   Connection* connection =
       port->CreateConnection(remote_candidate, PortInterface::ORIGIN_THIS_PORT);
   if (!connection) {
-    ASSERT(false);
+    // This could happen in some scenarios. For example, a TurnPort may have
+    // had a refresh request timeout, so it won't create connections.
     port->SendBindingErrorResponse(stun_msg, address, STUN_ERROR_SERVER_ERROR,
                                    STUN_ERROR_REASON_SERVER_ERROR);
     return;
   }
 
   LOG(LS_INFO) << "Adding connection from "
                << (remote_candidate_is_new ? "peer reflexive" : "resurrected")
                << " candidate: " << remote_candidate.ToString();
   AddConnection(connection);
   connection->HandleBindingRequest(stun_msg);
@@ skipping 1298 matching lines @@
 
   // During the initial state when nothing has been pinged yet, return the first
   // one in the ordered |connections_|.
   return *(std::find_if(connections_.begin(), connections_.end(),
                         [conn1, conn2](Connection* conn) {
                           return conn == conn1 || conn == conn2;
                         }));
 }
 
 }  // namespace cricket