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

chrome/test/chromedriver/keycode_text_conversion.h

Index: chrome/test/chromedriver/keycode_text_conversion.h
diff --git a/chrome/test/chromedriver/keycode_text_conversion.h b/chrome/test/chromedriver/keycode_text_conversion.h
index 294a8b783fc5bf6c7f15d5b03a01046b2d1134fe..915674e9f8122237dd83cd9cb752ed1d992e8a4f 100644
--- a/chrome/test/chromedriver/keycode_text_conversion.h
+++ b/chrome/test/chromedriver/keycode_text_conversion.h
@@ -27,7 +27,7 @@ bool ConvertKeyCodeToText(ui::KeyboardCode key_code,
 // 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);