Fix net_export.h includes.

net/proxy/proxy_script_fetcher_impl.h

 // Copyright (c) 2012 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_SCRIPT_FETCHER_IMPL_H_
 #define NET_PROXY_PROXY_SCRIPT_FETCHER_IMPL_H_
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
+#include "net/base/net_export.h"
 #include "net/proxy/proxy_script_fetcher.h"
 #include "net/url_request/url_request.h"
 
 class GURL;
 
 namespace net {
 
 class URLRequestContext;
 
 // Implementation of ProxyScriptFetcher that downloads scripts using the
@@ skipping 98 matching lines @@
   // Factory for creating the time-out task. This takes care of revoking
   // outstanding tasks when |this| is deleted.
   base::WeakPtrFactory<ProxyScriptFetcherImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProxyScriptFetcherImpl);
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_PROXY_SCRIPT_FETCHER_IMPL_H_