Cleanup: Remove unneeded forward declararations in net.

net/proxy/proxy_service.h

 // Copyright (c) 2011 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 NET_PROXY_PROXY_SERVICE_H_
 #define NET_PROXY_PROXY_SERVICE_H_
 #pragma once
 
+#include <string>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/non_thread_safe.h"
 #include "net/base/completion_callback.h"
 #include "net/base/load_states.h"
 #include "net/base/net_export.h"
 #include "net/base/net_log.h"
 #include "net/base/network_change_notifier.h"
 #include "net/proxy/proxy_config_service.h"
 #include "net/proxy/proxy_info.h"
 #include "net/proxy/proxy_server.h"
 
 class GURL;
 class MessageLoop;
 
 namespace net {
 
 class DhcpProxyScriptFetcher;
 class HostResolver;
 class InitProxyResolver;
 class NetworkDelegate;
 class ProxyResolver;
 class ProxyScriptFetcher;
-class URLRequestContext;
 
 // This class can be used to resolve the proxy server to use when loading a
 // HTTP(S) URL.  It uses the given ProxyResolver to handle the actual proxy
 // resolution.  See ProxyResolverV8 for example.
 class NET_EXPORT ProxyService : public NetworkChangeNotifier::IPAddressObserver,
                                 public ProxyConfigService::Observer,
                                 NON_EXPORTED_BASE(public base::NonThreadSafe) {
  public:
   // The instance takes ownership of |config_service| and |resolver|.
   // |net_log| is a possibly NULL destination to send log events to. It must
@@ skipping 352 matching lines @@
 
   base::WaitableEvent event_;
   OldCompletionCallbackImpl<SyncProxyServiceHelper> callback_;
   ProxyInfo proxy_info_;
   int result_;
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_PROXY_SERVICE_H_