[DomKey] Support Japanese (JIS) layout special 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 178 matching lines @@
   VKEY_OEM_4 = 0xDB,
   VKEY_OEM_5 = 0xDC,
   VKEY_OEM_6 = 0xDD,
   VKEY_OEM_7 = 0xDE,
   VKEY_OEM_8 = 0xDF,
   VKEY_OEM_102 = 0xE2,
   VKEY_OEM_103 = 0xE3,  // GTV KEYCODE_MEDIA_REWIND
   VKEY_OEM_104 = 0xE4,  // GTV KEYCODE_MEDIA_FAST_FORWARD
   VKEY_PROCESSKEY = 0xE5,
   VKEY_PACKET = 0xE7,
+  VKEY_OEM_ATTN = 0xF0,
+  VKEY_OEM_FINISH = 0xF1,
+  VKEY_OEM_COPY = 0xF2,

[Wez, 2016/07/07 18:25:51]

Since these have not-very-helpful names, can we add comments to explain their
actual use, as we have done above for the GTV OEM codes?

[chongz, 2016/07/07 22:18:08]

Done.

   VKEY_DBE_SBCSCHAR = 0xF3,
   VKEY_DBE_DBCSCHAR = 0xF4,
+  VKEY_OEM_BACKTAB = 0xF5,
   VKEY_ATTN = 0xF6,
   VKEY_CRSEL = 0xF7,
   VKEY_EXSEL = 0xF8,
   VKEY_EREOF = 0xF9,
   VKEY_PLAY = 0xFA,
   VKEY_ZOOM = 0xFB,
   VKEY_NONAME = 0xFC,
   VKEY_PA1 = 0xFD,
   VKEY_OEM_CLEAR = 0xFE,
   VKEY_UNKNOWN = 0,
@@ skipping 12 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_