chromeos: Cleanup class/struct fwd declarations

chromeos/network/proxy/proxy_config_handler.h

 // Copyright (c) 2013 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_HANDLER_H_
 #define CHROMEOS_NETWORK_PROXY_PROXY_CONFIG_HANDLER_H_
 
 #include <memory>
 
 #include "chromeos/chromeos_export.h"
 #include "components/onc/onc_constants.h"
 
-class PrefRegistrySimple;
 class PrefService;
 class ProxyConfigDictionary;
 
-namespace user_prefs {
-class PrefRegistrySyncable;
-}
-
 namespace chromeos {
 
 class NetworkState;
 
 namespace proxy_config {
 
 // Get the proxy configuration including per-network policies for network
 // |network|. If |profile_prefs| is NULL, then only shared settings (and device
 // policy) are respected. This is e.g. the case for the signin screen and the
 // system request context.
 CHROMEOS_EXPORT std::unique_ptr<ProxyConfigDictionary> GetProxyConfigForNetwork(
     const PrefService* profile_prefs,
     const PrefService* local_state_prefs,
     const NetworkState& network,
     ::onc::ONCSource* onc_source);
 
 CHROMEOS_EXPORT void SetProxyConfigForNetwork(
     const ProxyConfigDictionary& proxy_config,
     const NetworkState& network);
 
 }  // namespace proxy_config
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_NETWORK_PROXY_PROXY_CONFIG_HANDLER_H_