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

ash/system/chromeos/brightness/tray_brightness.h

-// 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.
-
-#ifndef ASH_SYSTEM_CHROMEOS_BRIGHTNESS_TRAY_BRIGHTNESS_H_
-#define ASH_SYSTEM_CHROMEOS_BRIGHTNESS_TRAY_BRIGHTNESS_H_
-
-#include "ash/common/system/tray/system_tray_item.h"
-#include "base/macros.h"
-#include "base/memory/weak_ptr.h"
-#include "chromeos/dbus/power_manager_client.h"
-
-namespace ash {
-namespace tray {
-class BrightnessView;
-}
-
-class ASH_EXPORT TrayBrightness
-    : public SystemTrayItem,
-      public chromeos::PowerManagerClient::Observer {
- public:
-  explicit TrayBrightness(SystemTray* system_tray);
-  ~TrayBrightness() override;
-
- private:
-  friend class TrayBrightnessTest;
-
-  // Sends a request to get the current screen brightness so |current_percent_|
-  // can be initialized.
-  void GetInitialBrightness();
-
-  // Updates |current_percent_| with the initial brightness requested by
-  // GetInitialBrightness(), if we haven't seen the brightness already in the
-  // meantime.
-  void HandleInitialBrightness(double percent);
-
-  // Overridden from SystemTrayItem.
-  views::View* CreateTrayView(LoginStatus status) override;
-  views::View* CreateDefaultView(LoginStatus status) override;
-  views::View* CreateDetailedView(LoginStatus status) override;
-  void DestroyTrayView() override;
-  void DestroyDefaultView() override;
-  void DestroyDetailedView() override;
-  void UpdateAfterLoginStatusChange(LoginStatus status) override;
-  bool ShouldHideArrow() const override;
-  bool ShouldShowShelf() const override;
-
-  // Overriden from PowerManagerClient::Observer.
-  void BrightnessChanged(int level, bool user_initiated) override;
-
-  void HandleBrightnessChanged(double percent, bool user_initiated);
-
-  tray::BrightnessView* brightness_view_;
-
-  // Brightness level in the range [0.0, 100.0] that we've heard about most
-  // recently.
-  double current_percent_;
-
-  // Has |current_percent_| been initialized?
-  bool got_current_percent_;
-
-  base::WeakPtrFactory<TrayBrightness> weak_ptr_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(TrayBrightness);
-};
-
-}  // namespace ash
-
-#endif  // ASH_SYSTEM_CHROMEOS_BRIGHTNESS_TRAY_BRIGHTNESS_H_