Fix potential crashes in NetworkHandler code

chromeos/network/host_resolver_impl_chromeos.cc

 // 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.
 
 #include "chromeos/network/host_resolver_impl_chromeos.h"
 
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/sys_info.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/values.h"
 #include "chromeos/network/device_state.h"
 #include "chromeos/network/network_handler.h"
 #include "chromeos/network/network_state.h"
 #include "chromeos/network/network_state_handler.h"
 #include "chromeos/network/network_state_handler_observer.h"
 #include "net/base/address_list.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
 
 namespace chromeos {
 
 // HostResolverImplChromeOS::NetworkStateHandlerObserver
 //
 // An instance of this class is created on the NetworkHandler (UI) thread and
 // manages its own lifetime, destroying itself when NetworkStateHandlerObserver
-// ::IsShuttingDown() gets called.
+// ::OnShuttingDown() gets called.
 
 class HostResolverImplChromeOS::NetworkObserver
     : public chromeos::NetworkStateHandlerObserver {
  public:
   static void Create(
       const base::WeakPtr<HostResolverImplChromeOS>& resolver,
       scoped_refptr<base::SingleThreadTaskRunner> resolver_task_runner,
       NetworkStateHandler* network_state_handler) {
     new NetworkObserver(resolver, resolver_task_runner, network_state_handler);
   }
@@ skipping 49 matching lines @@
       } else {
         LOG(ERROR) << "DefaultNetworkChanged: IPConfigs missing properties: "
                    << network->path();
       }
     }
     DVLOG(2) << "DefaultNetworkChanged: " << network->name()
              << " IPv4: " << ipv4_address << " IPv6: " << ipv6_address;
     CallResolverSetIpAddress(ipv4_address, ipv6_address);
   }
 
-  void IsShuttingDown() override { delete this; }
+  void OnShuttingDown() override { delete this; }
 
   void CallResolverSetIpAddress(const std::string& ipv4_address,
                                 const std::string& ipv6_address) {
     resolver_task_runner_->PostTask(
         FROM_HERE, base::Bind(&NetworkObserver::SetIpAddressOnResolverThread,
                               weak_ptr_factory_resolver_thread_.GetWeakPtr(),
                               ipv4_address, ipv6_address));
   }
 
   void SetIpAddressOnResolverThread(const std::string& ipv4_address,
@@ skipping 91 matching lines @@
 scoped_ptr<net::HostResolver>
 HostResolverImplChromeOS::CreateHostResolverForTest(
     scoped_refptr<base::SingleThreadTaskRunner> network_handler_task_runner,
     NetworkStateHandler* network_state_handler) {
   Options options;
   return scoped_ptr<net::HostResolver>(new HostResolverImplChromeOS(
       network_handler_task_runner, network_state_handler, options, NULL));
 }
 
 }  // namespace chromeos