Remove enable Drive offline system tray UI.

ash/system/chromeos/drive/tray_drive_notice.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_DRIVE_TRAY_DRIVE_NOTICE_H_
-#define ASH_SYSTEM_DRIVE_TRAY_DRIVE_NOTICE_H_
-
-#include "ash/system/drive/drive_observer.h"
-#include "ash/system/tray/tray_image_item.h"
-#include "ash/system/tray/tray_item_more.h"
-#include "base/timer/timer.h"
-
-namespace ash {
-namespace internal {
-
-class DriveNoticeDetailedView;
-
-// A tray item shown to the user as a notice that Google Drive offline mode has
-// been enabled automatically. This tray item is mainly informational and is
-// automatically dismissed after a short period of time.
-class ASH_EXPORT TrayDriveNotice : public TrayImageItem,
-                                   public DriveObserver {
- public:
-  explicit TrayDriveNotice(SystemTray* system_tray);
-  virtual ~TrayDriveNotice();
-
-  views::View* GetTrayView();
-  views::View* default_view() { return default_view_; }
-  views::View* detailed_view() { return detailed_view_; }
-
-  // Set the time the tray item is visible after opting-in for testing.
-  void SetTimeVisibleForTest(int time_visible_secs);
-
- private:
-  void HideNotice();
-
-  // Overridden from TrayImageItem.
-  virtual bool GetInitialVisibility() OVERRIDE;
-
-  // Overridden from SystemTrayItem.
-  virtual views::View* CreateDefaultView(user::LoginStatus status) OVERRIDE;
-  virtual views::View* CreateDetailedView(user::LoginStatus status) OVERRIDE;
-  virtual void DestroyDefaultView() OVERRIDE;
-  virtual void DestroyDetailedView() OVERRIDE;
-  virtual void UpdateAfterLoginStatusChange(user::LoginStatus status) OVERRIDE;
-
-  // Overridden from DriveObserver.
-  virtual void OnDriveJobUpdated(const DriveOperationStatus& status) OVERRIDE;
-  virtual void OnDriveOfflineEnabled() OVERRIDE;
-
-  views::View* default_view_;
-  views::View* detailed_view_;
-  base::OneShotTimer<TrayDriveNotice> visibility_timer_;
-  bool showing_item_;
-  int time_visible_secs_;
-
-  DISALLOW_COPY_AND_ASSIGN(TrayDriveNotice);
-};
-
-}  // namespace internal
-}  // namespace ash
-
-#endif  // ASH_SYSTEM_DRIVE_TRAY_DRIVE_NOTICE_H_