Handle F6 and F7 (brightness keys) in ash [part 3 of 3].

ash/accelerators/accelerator_controller.cc

Index: ash/accelerators/accelerator_controller.cc
diff --git a/ash/accelerators/accelerator_controller.cc b/ash/accelerators/accelerator_controller.cc
index 0f24273e6d005eb35c646f1fe9624f76c98684d0..28675af1345c96d0b26488a921051e968c383b00 100644
--- a/ash/accelerators/accelerator_controller.cc
+++ b/ash/accelerators/accelerator_controller.cc
@@ -60,6 +60,8 @@ struct AcceleratorData {
   { ui::VKEY_TAB, true, false, true, CYCLE_BACKWARD },
   { ui::VKEY_F5, false, false, false, CYCLE_FORWARD },
 #if defined(OS_CHROMEOS)
+  { ui::VKEY_BRIGHTNESS_DOWN, false, false, false, BRIGHTNESS_DOWN },
+  { ui::VKEY_BRIGHTNESS_UP, false, false, false, BRIGHTNESS_UP },
   { ui::VKEY_L, true, true, false, LOCK_SCREEN },
 #endif
   { ui::VKEY_Q, true, true, false, EXIT },
@@ -69,8 +71,6 @@ struct AcceleratorData {
   { ui::VKEY_PRINT, false, false, false, TAKE_SCREENSHOT },
   // On Chrome OS, Search key is mapped to LWIN.
   { ui::VKEY_LWIN, true, false, false, TOGGLE_CAPS_LOCK },
-  // TODO(yusukes): Support multimedia keys for controlling brightness on an
-  // external USB keyboard.
   { ui::VKEY_F6, false, false, false, BRIGHTNESS_DOWN },
   { ui::VKEY_F7, false, false, false, BRIGHTNESS_UP },
   { ui::VKEY_F8, false, false, false, VOLUME_MUTE },