mash: Migrate ShelfLockingManager to ash/common.

ash/shelf/shelf_locking_manager.h

-// Copyright 2016 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_SHELF_SHELF_LOCKING_MANAGER_H_
-#define ASH_SHELF_SHELF_LOCKING_MANAGER_H_
-
-#include "ash/ash_export.h"
-#include "ash/common/session/session_state_observer.h"
-#include "ash/common/shelf/shelf_types.h"
-#include "ash/common/shell_observer.h"
-#include "ash/wm/lock_state_observer.h"
-
-namespace ash {
-
-class Shelf;
-
-// ShelfLockingManager observes screen and session events to [un]lock the shelf.
-class ASH_EXPORT ShelfLockingManager : public ShellObserver,
-                                       public SessionStateObserver,
-                                       public LockStateObserver {
- public:
-  explicit ShelfLockingManager(Shelf* shelf);
-  ~ShelfLockingManager() override;
-
-  bool is_locked() const { return session_locked_ || screen_locked_; }
-  void set_stored_alignment(ShelfAlignment value) { stored_alignment_ = value; }
-
-  // ShellObserver:
-  void OnLockStateChanged(bool locked) override;
-
-  // SessionStateObserver:
-  void SessionStateChanged(SessionStateDelegate::SessionState state) override;
-
-  // LockStateObserver:
-  void OnLockStateEvent(EventType event) override;
-
- private:
-  // Update the shelf state for session and screen lock changes.
-  void UpdateLockedState();
-
-  Shelf* shelf_;
-  bool session_locked_ = false;
-  bool screen_locked_ = false;
-  ShelfAlignment stored_alignment_ = SHELF_ALIGNMENT_BOTTOM;
-
-  DISALLOW_COPY_AND_ASSIGN(ShelfLockingManager);
-};
-
-}  // namespace ash
-
-#endif  // ASH_SHELF_SHELF_LOCKING_MANAGER_H_