Add VKEY_POWER to the POSIX KeyboardCode enum.

ui/base/keycodes/keyboard_code_conversion_x.cc

Index: ui/base/keycodes/keyboard_code_conversion_x.cc
diff --git a/ui/base/keycodes/keyboard_code_conversion_x.cc b/ui/base/keycodes/keyboard_code_conversion_x.cc
index 2bfedb8a8dcbdbd0473b8c238fcbd791e8ab3ae7..3548dcf8453eceffe3c722786c68b5a571f6e2ae 100644
--- a/ui/base/keycodes/keyboard_code_conversion_x.cc
+++ b/ui/base/keycodes/keyboard_code_conversion_x.cc
@@ -388,6 +388,8 @@ KeyboardCode KeyboardCodeFromXKeysym(unsigned int keysym) {
       return VKEY_MEDIA_LAUNCH_APP2;
     case XF86XK_WLAN:
       return VKEY_WLAN;
+    case XF86XK_PowerOff:
+      return VKEY_POWER;
     case XF86XK_MonBrightnessDown:
       return VKEY_BRIGHTNESS_DOWN;
     case XF86XK_MonBrightnessUp:
@@ -744,6 +746,8 @@ int XKeysymForWindowsKeyCode(KeyboardCode keycode, bool shift) {
       return XF86XK_LaunchB;
     case VKEY_WLAN:
       return XF86XK_WLAN;
+    case VKEY_POWER:
+      return XF86XK_PowerOff;
     case VKEY_BRIGHTNESS_DOWN:
       return XF86XK_MonBrightnessDown;
     case VKEY_BRIGHTNESS_UP: