mash: Migrate some system user files to common.

ash/shell.h

 // Copyright (c) 2012 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_SHELL_H_
 #define ASH_SHELL_H_
 
 #include <memory>
 #include <utility>
 #include <vector>
 
 #include "ash/ash_export.h"
 #include "ash/common/shelf/shelf_types.h"
 #include "ash/common/wm_shell_common.h"
 #include "ash/metrics/user_metrics_recorder.h"
-#include "ash/system/user/login_status.h"
 #include "ash/wm/cursor_manager_chromeos.h"
 #include "ash/wm/system_modal_container_event_filter_delegate.h"
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "ui/aura/window.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/display/screen.h"
@@ skipping 75 matching lines @@
 class EventTransformationHandler;
 class FirstRunHelper;
 class GPUSupport;
 class HighContrastController;
 class KeyboardUI;
 class KeyboardUMAEventFilter;
 class LastWindowClosedLogoutReminder;
 class LinkHandlerModelFactory;
 class LocaleNotificationController;
 class LockStateController;
+enum class LoginStatus;
 class LogoutConfirmationController;
 class MagnificationController;
 class MaximizeModeController;
 class MaximizeModeWindowManager;
 class MediaDelegate;
 class MouseCursorEventFilter;
 class MruWindowTracker;
 class NewWindowDelegate;
 class OverlayEventFilter;
 class PartialMagnificationController;
@@ skipping 644 matching lines @@
   bool in_mus_ = false;
 
   std::unique_ptr<KeyboardUI> keyboard_ui_;
 
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_H_