Move PortAllocator creation out of LibjingleTransportFactory.

remoting/protocol/transport_config.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/protocol/transport_config.h"
 
 namespace remoting {
 namespace protocol {
 
-TransportConfig::TransportConfig()
-    : nat_traversal_mode(NAT_TRAVERSAL_DISABLED),
-      min_port(0),
-      max_port(0) {
+TransportConfig::TransportConfig() {
 }
 
 TransportConfig::~TransportConfig() {
 }
 
 }  // namespace protocol
 }  // namespace remoting