chromeos: Move files in //ash/common to //ash, part 1

ash/common/system/chromeos/session/logout_button_tray.h

-// Copyright 2014 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_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_BUTTON_TRAY_H_
-#define ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_BUTTON_TRAY_H_
-
-#include "ash/ash_export.h"
-#include "ash/common/login_status.h"
-#include "ash/common/system/chromeos/session/logout_button_observer.h"
-#include "ash/common/system/tray/tray_background_view.h"
-#include "base/macros.h"
-#include "base/time/time.h"
-#include "ui/views/controls/button/button.h"
-
-namespace views {
-class LabelButton;
-}
-
-namespace ash {
-
-// Adds a logout button to the launcher's status area if enabled by the
-// kShowLogoutButtonInTray pref.
-class ASH_EXPORT LogoutButtonTray : public TrayBackgroundView,
-                                    public LogoutButtonObserver {
- public:
-  explicit LogoutButtonTray(WmShelf* wm_shelf);
-  ~LogoutButtonTray() override;
-
-  // TrayBackgroundView:
-  void SetShelfAlignment(ShelfAlignment alignment) override;
-  base::string16 GetAccessibleNameForTray() override;
-  void HideBubbleWithView(const views::TrayBubbleView* bubble_view) override;
-  void ClickedOutsideBubble() override;
-  void ButtonPressed(views::Button* sender, const ui::Event& event) override;
-
-  // LogoutButtonObserver:
-  void OnShowLogoutButtonInTrayChanged(bool show) override;
-  void OnLogoutDialogDurationChanged(base::TimeDelta duration) override;
-
-  void UpdateAfterLoginStatusChange(LoginStatus login_status);
-
- private:
-  void UpdateVisibility();
-  void UpdateButtonTextAndImage(LoginStatus login_status,
-                                ShelfAlignment alignment);
-
-  views::LabelButton* button_;
-  LoginStatus login_status_;
-  bool show_logout_button_in_tray_;
-  base::TimeDelta dialog_duration_;
-
-  DISALLOW_COPY_AND_ASSIGN(LogoutButtonTray);
-};
-
-}  // namespace ash
-
-#endif  // ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_BUTTON_TRAY_H_