Use a direct include of strings headers in chrome/test/.

chrome/test/webdriver/keycode_text_conversion_gtk.cc

 // 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.
 
 #include "chrome/test/webdriver/keycode_text_conversion.h"
 
 #include <gdk/gdk.h>
 
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/common/automation_constants.h"
 #include "ui/base/keycodes/keyboard_code_conversion_gtk.h"
 
 namespace webdriver {
 
 std::string ConvertKeyCodeToText(ui::KeyboardCode key_code, int modifiers) {
   // |gdk_keyval_to_upper| does not convert some keys like '1' to '!', so
   // provide |ui::GdkKeyCodeForWindowsKeyCode| with our shift state as well,
   // which will do basic conversions like it for us.
@@ skipping 37 matching lines @@
 
   if (is_special_symbol || key_utf32 != g_unichar_tolower(key_utf32))
     *necessary_modifiers = automation::kShiftKeyMask;
   ui::KeyboardCode code = ui::WindowsKeyCodeForGdkKeyCode(gdk_key_code);
   if (code != ui::VKEY_UNKNOWN)
     *key_code = code;
   return code != ui::VKEY_UNKNOWN;
 }
 
 }  // namespace webdriver