components: Cleanup class/struct fwd declarations

components/data_reduction_proxy/core/browser/data_reduction_proxy_configurator.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 COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_CONFIGURATOR_H_
 #define COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_CONFIGURATOR_H_
 
 #include <string>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/threading/thread_checker.h"
 #include "net/proxy/proxy_config.h"
 
 namespace net {
 class NetLog;
-class ProxyInfo;
 class ProxyServer;
-class ProxyService;
 }
 
-class PrefService;
-
 namespace data_reduction_proxy {
 
 class DataReductionProxyEventCreator;
 
 class DataReductionProxyConfigurator {
  public:
   // Constructs a configurator. |net_log| and |event_creator| are used to
   // track network and Data Reduction Proxy events respectively, must not be
   // null, and must outlive this instance.
   DataReductionProxyConfigurator(net::NetLog* net_log,
@@ skipping 46 matching lines @@
 
   // Enforce usage on the IO thread.
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(DataReductionProxyConfigurator);
 };
 
 }  // namespace data_reduction_proxy
 
 #endif  // COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_CONFIGURATOR_H_