[DomKey] Use VK->DomKey mapping for non-printable keys

ui/events/keycodes/keyboard_codes_win.h

 // 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.
 
 #ifndef UI_EVENTS_KEYCODES_KEYBOARD_CODES_WIN_H_
 #define UI_EVENTS_KEYCODES_KEYBOARD_CODES_WIN_H_
 
 #include <windows.h>
 #include <ime.h>
 
 namespace ui {
 
 enum KeyboardCode {
+  VKEY_CANCEL = VK_CANCEL,
   VKEY_BACK = VK_BACK,
   VKEY_TAB = VK_TAB,
   VKEY_CLEAR = VK_CLEAR,
   VKEY_RETURN = VK_RETURN,
   VKEY_SHIFT = VK_SHIFT,
   VKEY_CONTROL = VK_CONTROL,
   VKEY_MENU = VK_MENU,  // a.k.a. ALT
   VKEY_PAUSE = VK_PAUSE,
   VKEY_CAPITAL = VK_CAPITAL,
   VKEY_KANA = VK_KANA,
@@ skipping 159 matching lines @@
   VKEY_UNKNOWN = 0,
 
   // Windows does not have a specific key code for AltGr. We use the unused
   // VK_OEM_AX to represent AltGr, matching the behaviour of Firefox on Linux.
   VKEY_ALTGR = VK_OEM_AX,
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_KEYCODES_KEYBOARD_CODES_WIN_H_