Update some uses of char16 to use the base:: namespace.

chrome/test/chromedriver/keycode_text_conversion.h

 // Copyright (c) 2013 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_CHROMEDRIVER_KEYCODE_TEXT_CONVERSION_H_
 #define CHROME_TEST_CHROMEDRIVER_KEYCODE_TEXT_CONVERSION_H_
 
 #include <string>
 
 #include "base/strings/string16.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 
 // These functions only support conversion of characters in the BMP
 // (Basic Multilingual Plane).
 
 // Coverts a key code and modifiers to the UTF8 text that would be produced
 // with the current keyboard layout, or "" if no character would be produced.
 // Returns "" if the produced text contains characters outside the BMP. If an
 // error occurs |error_msg| will be set to the error message and will return
 // false.
 bool ConvertKeyCodeToText(ui::KeyboardCode key_code,
                           int modifiers,
                           std::string* text,
                           std::string* error_msg);
 
 // Converts a character to the key code and modifiers that would produce
 // the character using the current keyboard layout. Returns true on success.
 // If an error occurs |error_msg| will be set to the error message, otherwise
 // it will be set to the empty string.
-bool ConvertCharToKeyCode(char16 key,
+bool ConvertCharToKeyCode(base::char16 key,
                           ui::KeyboardCode* key_code,
                           int *necessary_modifiers,
                           std::string* error_msg);
 
 #endif  // CHROME_TEST_CHROMEDRIVER_KEYCODE_TEXT_CONVERSION_H_