Add blocking IO restriction on the network thread.

remoting/host/host_signaling_manager.h

 // Copyright 2014 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.
 
 #ifndef REMOTING_HOST_HOST_SIGNALING_MANAGER_H_
 #define REMOTING_HOST_HOST_SIGNALING_MANAGER_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 72 matching lines @@
   // |host_offline_reason|, or the |timeout| is reached.  Deleting
   // |this| will release |network_task_runner_| and allow the host
   // process to exit.
   void SendHostOfflineReasonAndDelete(const std::string& host_offline_reason,
                                       const base::TimeDelta& timeout);
 
  private:
   HostSignalingManager(
       scoped_ptr<base::WeakPtrFactory<Listener>> weak_factory_for_listener,
       const scoped_refptr<AutoThreadTaskRunner>& network_task_runner,
-      scoped_ptr<net::NetworkChangeNotifier> network_change_notifier,
       scoped_ptr<SignalStrategy> signal_strategy,
       scoped_ptr<SignalingConnector> signaling_connector,
       scoped_ptr<HeartbeatSender> heartbeat_sender);
 
   void OnHostOfflineReasonAck(bool success);
 
   // Used to bind HeartbeatSender and SignalingConnector callbacks to |listener|
   // in a way that allows "detaching" the |listener| when either |this| is
   // destroyed or when SendHostOfflineReasonAndDelete method is called.
   scoped_ptr<base::WeakPtrFactory<Listener>> weak_factory_for_listener_;
 
   // By holding a reference to |network_task_runner_|, HostSignalingManager is
   // extending the lifetime of the host process.  This is needed for the case
   // where an instance of HostProcess has already been destroyed, but we want
   // to keep the process running while we try to establish a connection and send
   // host-offline-reason.
   scoped_refptr<AutoThreadTaskRunner> network_task_runner_;
 
-  // Order of fields below is important for destroying them in the right order.
-  // - |heartbeat_sender_| and |signaling_connector_| have to be destroyed
-  //   before |signal_strategy_| because their destructors need to call
-  //   signal_strategy_->RemoveListener(this)
-  // - |signaling_connector_| has to be destroyed before
-  //   |network_change_notifier_| because its destructor needs to deregister
-  //   network change notifications
-  scoped_ptr<net::NetworkChangeNotifier> network_change_notifier_;
+  // |heartbeat_sender_| and |signaling_connector_| have to be destroyed before
+  // |signal_strategy_| because their destructors need to call
+  // signal_strategy_->RemoveListener(this)
   scoped_ptr<SignalStrategy> signal_strategy_;
   scoped_ptr<SignalingConnector> signaling_connector_;
   scoped_ptr<HeartbeatSender> heartbeat_sender_;
 
   DISALLOW_COPY_AND_ASSIGN(HostSignalingManager);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_HOST_SIGNALING_MANAGER_H_