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

ui/events/keycodes/keyboard_codes_posix.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.
 
 /*
  * Copyright (C) 2006 Michael Emmel mike.emmel@gmail.com. All rights reserved.
  * Copyright (C) 2008, 2009 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ skipping 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef UI_EVENTS_KEYCODES_KEYBOARD_CODES_POSIX_H_
 #define UI_EVENTS_KEYCODES_KEYBOARD_CODES_POSIX_H_
 
 namespace ui {
 
 enum KeyboardCode {
+  VKEY_CANCEL = 0x03,
   VKEY_BACK = 0x08,
   VKEY_TAB = 0x09,
   VKEY_BACKTAB = 0x0A,
   VKEY_CLEAR = 0x0C,
   VKEY_RETURN = 0x0D,
   VKEY_SHIFT = 0x10,
   VKEY_CONTROL = 0x11,
   VKEY_MENU = 0x12,
   VKEY_PAUSE = 0x13,
   VKEY_CAPITAL = 0x14,
@@ skipping 175 matching lines @@
   // Linux.
   VKEY_ALTGR = 0xE1,
   // Windows does not have a specific key code for Compose. We use the unused
   // 0xE6 (VK_ICO_CLEAR) code to represent Compose.
   VKEY_COMPOSE = 0xE6,
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_KEYCODES_KEYBOARD_CODES_POSIX_H_