Fix net_export.h includes.

net/proxy/polling_proxy_config_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_POLLING_PROXY_CONFIG_SERVICE_H_
 #define NET_PROXY_POLLING_PROXY_CONFIG_SERVICE_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
+#include "net/base/net_export.h"
 #include "net/proxy/proxy_config_service.h"
 
 namespace net {
 
 // PollingProxyConfigService is a base class for creating ProxyConfigService
 // implementations that use polling to notice when settings have change.
 //
 // It runs code to get the current proxy settings on a background worker
 // thread, and notifies registered observers when the value changes.
 class NET_EXPORT_PRIVATE PollingProxyConfigService : public ProxyConfigService {
@@ skipping 25 matching lines @@
  private:
   class Core;
   scoped_refptr<Core> core_;
 
   DISALLOW_COPY_AND_ASSIGN(PollingProxyConfigService);
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_POLLING_PROXY_CONFIG_SERVICE_H_