Move ASCIIToWide and ASCIIToUTF16 to utf_string_conversions.h. I've found it...

net/url_request/url_request_unittest.h

 // Copyright (c) 2010 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_URL_REQUEST_UNITTEST_H_
 #define NET_URL_REQUEST_URL_REQUEST_UNITTEST_H_
 #pragma once
 
 #include <stdlib.h>
 
 #include <sstream>
 #include <string>
 #include <vector>
 
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
+#include "base/string_util.h"
 #include "base/thread.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "base/waitable_event.h"
 #include "net/base/cookie_monster.h"
 #include "net/base/cookie_policy.h"
 #include "net/base/host_resolver.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/base/ssl_config_service_defaults.h"
@@ skipping 572 matching lines @@
       return NULL;
     }
     return test_server;
   }
 
  private:
   ~FTPTestServer() {}
 };
 
 #endif  // NET_URL_REQUEST_URL_REQUEST_UNITTEST_H_