Automated IWYU fix for TaskRunner includes.

chromeos/network/proxy/proxy_config_service_impl.h

 // 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.
 
 #ifndef CHROMEOS_NETWORK_PROXY_PROXY_CONFIG_SERVICE_IMPL_H_
 #define CHROMEOS_NETWORK_PROXY_PROXY_CONFIG_SERVICE_IMPL_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "base/single_thread_task_runner.h"
 #include "chromeos/chromeos_export.h"
 #include "chromeos/network/network_state_handler_observer.h"
 #include "components/onc/onc_constants.h"
 #include "components/prefs/pref_change_registrar.h"
 #include "components/proxy_config/pref_proxy_config_tracker_impl.h"
 
 namespace chromeos {
 
 class NetworkState;
 
@@ skipping 83 matching lines @@
   PrefService* local_state_prefs_;
 
   base::WeakPtrFactory<ProxyConfigServiceImpl> pointer_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProxyConfigServiceImpl);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_NETWORK_PROXY_PROXY_CONFIG_SERVICE_IMPL_H_