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

chrome/test/webdriver/webdriver_key_converter.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 CHROME_TEST_WEBDRIVER_WEBDRIVER_KEY_CONVERTER_H_
 #define CHROME_TEST_WEBDRIVER_WEBDRIVER_KEY_CONVERTER_H_
 
 #include <string>
 #include <vector>
 
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "chrome/test/webdriver/webdriver_automation.h"
 #include "ui/base/keycodes/keyboard_codes.h"
 
 namespace webdriver {
 
 class Logger;
 
 // Convenience functions for creating |WebKeyEvent|s. Used by unittests.
 WebKeyEvent CreateKeyDownEvent(ui::KeyboardCode key_code, int modifiers);
 WebKeyEvent CreateKeyUpEvent(ui::KeyboardCode key_code, int modifiers);
@@ skipping 10 matching lines @@
 bool ConvertKeysToWebKeyEvents(const string16& keys,
                                const Logger& logger,
                                bool release_modifiers,
                                int* modifiers,
                                std::vector<WebKeyEvent>* key_events,
                                std::string* error_msg);
 
 }  // namespace webdriver
 
 #endif  // CHROME_TEST_WEBDRIVER_WEBDRIVER_KEY_CONVERTER_H_