Add shortcuts for keyboard brightness

ash/system/keyboard_brightness/keyboard_brightness_control_delegate.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.
+
+#ifndef ASH_SYSTEM_KEYBOARD_BRIGHTNESS_KEYBOARD_BRIGHTNESS_CONTROL_DELEGATE_H_
+#define ASH_SYSTEM_KEYBOARD_BRIGHTNESS_KEYBOARD_BRIGHTNESS_CONTROL_DELEGATE_H_
+#pragma once
+
+namespace ui {
+class Accelerator;
+}  // namespace ui
+
+namespace ash {
+
+// Delegate for controlling the keyboard brightness.
+class KeyboardBrightnessControlDelegate {
+ public:
+  virtual ~KeyboardBrightnessControlDelegate() {}
+
+  // Handles an accelerator-driven request to decrease or increase the keyboard
+  // brightness. Returns true if the brightness is changed.
+  virtual bool HandleKeyboardBrightnessDown(
+      const ui::Accelerator& accelerator) = 0;
+  virtual bool HandleKeyboardBrightnessUp(
+      const ui::Accelerator& accelerator) = 0;
+};
+
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_KEYBOARD_BRIGHTNESS_KEYBOARD_BRIGHTNESS_CONTROL_DELEGATE_H_