Bind a socket to a network if the network handle is set.

webrtc/base/networkmonitor.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.
  */
 
 #include "webrtc/base/networkmonitor.h"
 
 #include "webrtc/base/common.h"
 
 namespace {
 const uint32_t UPDATE_NETWORKS_MESSAGE = 1;
 
 // This is set by NetworkMonitorFactory::SetFactory and the caller of
 // NetworkMonitorFactory::SetFactory must be responsible for calling
 // ReleaseFactory to destroy the factory.
 rtc::NetworkMonitorFactory* network_monitor_factory = nullptr;
 }  // namespace
 
 namespace rtc {
 NetworkMonitorInterface::NetworkMonitorInterface() {}
 
 NetworkMonitorInterface::~NetworkMonitorInterface() {}
 
-NetworkMonitorBase::NetworkMonitorBase() : thread_(Thread::Current()) {}
+NetworkMonitorBase::NetworkMonitorBase() : thread_(nullptr) {}
 NetworkMonitorBase::~NetworkMonitorBase() {}
 
+void NetworkMonitorBase::Start() {

[pthatcher1, 2016/01/14 20:07:24]

Should we check to make sure Start() isn't called more than once?

[honghaiz3, 2016/01/15 01:00:38]

Removed this change. 

+  if (thread_ == nullptr) {
+    thread_ = Thread::Current();
+  }
+}
 void NetworkMonitorBase::OnNetworksChanged() {
   LOG(LS_VERBOSE) << "Network change is received at the network monitor";
+  ASSERT(thread_ != nullptr);
   thread_->Post(this, UPDATE_NETWORKS_MESSAGE);
 }
 
 void NetworkMonitorBase::OnMessage(Message* msg) {
   ASSERT(msg->message_id == UPDATE_NETWORKS_MESSAGE);
   SignalNetworksChanged();
 }
 
 NetworkMonitorFactory::NetworkMonitorFactory() {}
 NetworkMonitorFactory::~NetworkMonitorFactory() {}
 
 void NetworkMonitorFactory::SetFactory(NetworkMonitorFactory* factory) {
   if (network_monitor_factory != nullptr) {
     delete network_monitor_factory;
   }
   network_monitor_factory = factory;
 }
 
 void NetworkMonitorFactory::ReleaseFactory(NetworkMonitorFactory* factory) {
   if (factory == network_monitor_factory) {
     SetFactory(nullptr);
   }
 }
 
 NetworkMonitorFactory* NetworkMonitorFactory::GetFactory() {
   return network_monitor_factory;
 }
 
 }  // namespace rtc