mash: Migrate [Keyboard]Brightness code to ash/common.

ash/system/chromeos/brightness/brightness_controller_chromeos.cc

-// Copyright 2013 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.
-
-#include "ash/system/chromeos/brightness/brightness_controller_chromeos.h"
-
-#include "base/metrics/user_metrics.h"
-#include "chromeos/dbus/dbus_thread_manager.h"
-#include "chromeos/dbus/power_manager_client.h"
-#include "ui/base/accelerators/accelerator.h"
-
-namespace ash {
-namespace system {
-
-void BrightnessControllerChromeos::HandleBrightnessDown(
-    const ui::Accelerator& accelerator) {
-  if (accelerator.key_code() == ui::VKEY_BRIGHTNESS_DOWN)
-    base::RecordAction(base::UserMetricsAction("Accel_BrightnessDown_F6"));
-
-  chromeos::DBusThreadManager::Get()
-      ->GetPowerManagerClient()
-      ->DecreaseScreenBrightness(true);
-}
-
-void BrightnessControllerChromeos::HandleBrightnessUp(
-    const ui::Accelerator& accelerator) {
-  if (accelerator.key_code() == ui::VKEY_BRIGHTNESS_UP)
-    base::RecordAction(base::UserMetricsAction("Accel_BrightnessUp_F7"));
-
-  chromeos::DBusThreadManager::Get()
-      ->GetPowerManagerClient()
-      ->IncreaseScreenBrightness();
-}
-
-void BrightnessControllerChromeos::SetBrightnessPercent(double percent,
-                                                        bool gradual) {
-  chromeos::DBusThreadManager::Get()
-      ->GetPowerManagerClient()
-      ->SetScreenBrightnessPercent(percent, gradual);
-}
-
-void BrightnessControllerChromeos::GetBrightnessPercent(
-    const base::Callback<void(double)>& callback) {
-  chromeos::DBusThreadManager::Get()
-      ->GetPowerManagerClient()
-      ->GetScreenBrightnessPercent(callback);
-}
-
-}  // namespace system
-}  // namespace ash