Fix net_export.h includes.

net/url_request/file_protocol_handler.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_URL_REQUEST_FILE_PROTOCOL_HANDLER_H_
 #define NET_URL_REQUEST_FILE_PROTOCOL_HANDLER_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "net/base/net_export.h"
 #include "net/url_request/url_request_job_factory.h"
 
 class GURL;
 
 namespace base {
 class TaskRunner;
 }
 
 namespace net {
 
@@ skipping 14 matching lines @@
   bool IsSafeRedirectTarget(const GURL& location) const override;
 
  private:
   const scoped_refptr<base::TaskRunner> file_task_runner_;
   DISALLOW_COPY_AND_ASSIGN(FileProtocolHandler);
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_FILE_PROTOCOL_HANDLER_H_