Fix net_export.h includes.

net/proxy/proxy_config_service_win.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_CONFIG_SERVICE_WIN_H_
 #define NET_PROXY_PROXY_CONFIG_SERVICE_WIN_H_
 
 #include <windows.h>
 #include <winhttp.h>
 
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
+#include "net/base/net_export.h"
 #include "net/proxy/polling_proxy_config_service.h"
 
 namespace base {
 namespace win {
 class RegKey;
 }
 }  // namespace base.
 
 namespace net {
 
@@ skipping 48 matching lines @@
   static void SetFromIEConfig(
       ProxyConfig* config,
       const WINHTTP_CURRENT_USER_IE_PROXY_CONFIG& ie_config);
 
   RegKeyList keys_to_watch_;
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_PROXY_CONFIG_SERVICE_WIN_H_