[keyboard] Add DOM code mappings for keyboard brightness.

- Add new DOM |code| entries corresponding to the USB HID
  codes for keyboard brightness. See USB HID spec update [1]
- Updating the US English keyboard layout data to map
  codes to existing keyboard-brightness accelerator VKEYS.

[1] - https://www.usb.org/sites/default/files/hutrr73_-_fn_key_and_keyboard_backlight_brightness_0.pdf

Bug=1076241
TEST=manual

Change-Id: I79573145afbc8bdafbc6da6782cd99099c73bc13
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2202667Reviewed-by: Gary Kacmarcik <garykac@chromium.org>
Commit-Queue: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#770685}

ui/events/keycodes/dom/dom_code_data.inc

@@ -463,6 +463,9 @@ DOM_CODE_DECLARATION {
 
   // KEY_BRIGHTNESS* added in Linux 3.16
   // http://www.usb.org/developers/hidpage/HUTRR41.pdf
+  //
+  // Keyboard backlight/illumination spec update.
+  // https://www.usb.org/sites/default/files/hutrr73_-_fn_key_and_keyboard_backlight_brightness_0.pdf
   //            USB     evdev    XKB     Win     Mac   Code
   DOM_CODE(0x0c0060, 0x0166, 0x016e, 0x0000, 0xffff, NULL, INFO),
   DOM_CODE(0x0c0061, 0x0172, 0x017a, 0x0000, 0xffff, NULL, CLOSED_CAPTION_TOGGLE),
@@ -473,6 +476,8 @@ DOM_CODE_DECLARATION {
   DOM_CODE(0x0c0073, 0x0250, 0x0258, 0x0000, 0xffff, NULL, BRIGHTNESS_MINIMIUM),
   DOM_CODE(0x0c0074, 0x0251, 0x0259, 0x0000, 0xffff, NULL, BRIGHTNESS_MAXIMUM),
   DOM_CODE(0x0c0075, 0x00f4, 0x00fc, 0x0000, 0xffff, NULL, BRIGHTNESS_AUTO),
+  DOM_CODE(0x0c0079, 0x00e6, 0x00ee, 0x0000, 0xffff, NULL, KBD_ILLUM_UP),
+  DOM_CODE(0x0c007a, 0x00e5, 0x00ed, 0x0000, 0xffff, NULL, KBD_ILLUM_DOWN),
   DOM_CODE(0x0c0083, 0x0195, 0x019d, 0x0000, 0xffff, NULL, MEDIA_LAST),
   DOM_CODE(0x0c008c, 0x00a9, 0x00b1, 0x0000, 0xffff, NULL, LAUNCH_PHONE),
   DOM_CODE(0x0c008d, 0x016a, 0x0172, 0x0000, 0xffff, NULL, PROGRAM_GUIDE),

ui/events/keycodes/dom/keycode_converter_unittest.cc

@@ -24,10 +24,10 @@ namespace {
 // These are in the same order as the columns in dom_code_data.inc
 // as reflected in the DOM_CODE() macro below.
 const size_t expected_mapped_key_count[] = {
-  214,  // evdev
-  214,  // xkb
-  157,  // windows
-  119,  // mac
+    216,  // evdev
+    216,  // xkb
+    157,  // windows
+    119,  // mac
 };
 
 const size_t kNativeColumns = base::size(expected_mapped_key_count);

ui/events/keycodes/dom_us_layout_data.h

@@ -580,7 +580,10 @@ const struct DomCodeToKeyboardCodeEntry {
 #if defined(OS_POSIX)
     {DomCode::BRIGHTNESS_UP, VKEY_BRIGHTNESS_UP},  // 0x0C006F BrightnessUp
     {DomCode::BRIGHTNESS_DOWN,
-     VKEY_BRIGHTNESS_DOWN},  // 0x0C0070 BrightnessDown
+     VKEY_BRIGHTNESS_DOWN},                           // 0x0C0070 BrightnessDown
+    {DomCode::KBD_ILLUM_UP, VKEY_KBD_BRIGHTNESS_UP},  // 0x0C0079 KbdIllumUp
+    {DomCode::KBD_ILLUM_DOWN,
+     VKEY_KBD_BRIGHTNESS_DOWN},  // 0x0C007a KbdIllumDown
 #endif
     {DomCode::MEDIA_TRACK_NEXT,
      VKEY_MEDIA_NEXT_TRACK},  // 0x0C00B5 MediaTrackNext
@@ -642,8 +645,6 @@ const DomCodeToKeyboardCodeEntry kFallbackKeyboardCodeToDomCodeMap[] = {
     //  VKEY_OEM_104              // 0x0C00B3 MediaFastForward
     //
     // VKEYs with no corresponding DomCode, but a Linux evdev usage code:
-    //  VKEY_KBD_BRIGHTNESS_DOWN  //  evdev KEY_KBDILLUMDOWN
-    //  VKEY_KBD_BRIGHTNESS_UP    //  evdev KEY_KBDILLUMUP
     //  VKEY_WLAN                 //  evdev KEY_WLAN
     //
     // VKEYs with no corresponding DomCode and no obvious USB usage code: