Use scoped_refptr<SingleThreadTaskRunner> when initializing ProxyConfigService

net/proxy/proxy_config_service_mac.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 "net/proxy/proxy_config_service_mac.h"
 
 #include <CoreFoundation/CoreFoundation.h>
 #include <SystemConfiguration/SystemConfiguration.h>
 
 #include "base/bind.h"
@@ skipping 180 matching lines @@
     SCDynamicStoreRef store) {
   proxy_config_service_->SetDynamicStoreNotificationKeys(store);
 }
 
 void ProxyConfigServiceMac::Forwarder::OnNetworkConfigChange(
     CFArrayRef changed_keys) {
   proxy_config_service_->OnNetworkConfigChange(changed_keys);
 }
 
 ProxyConfigServiceMac::ProxyConfigServiceMac(
-    base::SingleThreadTaskRunner* io_thread_task_runner)
+    const scoped_refptr<base::SingleThreadTaskRunner>& io_thread_task_runner)
     : forwarder_(this),
       has_fetched_config_(false),
       helper_(new Helper(this)),
       io_thread_task_runner_(io_thread_task_runner) {
   DCHECK(io_thread_task_runner_.get());
   config_watcher_.reset(new NetworkConfigWatcherMac(&forwarder_));
 }
 
 ProxyConfigServiceMac::~ProxyConfigServiceMac() {
   DCHECK(io_thread_task_runner_->BelongsToCurrentThread());
@@ skipping 63 matching lines @@
   // Keep track of the last value we have seen.
   has_fetched_config_ = true;
   last_config_fetched_ = new_config;
 
   // Notify all the observers.
   FOR_EACH_OBSERVER(Observer, observers_,
                     OnProxyConfigChanged(new_config, CONFIG_VALID));
 }
 
 }  // namespace net