Reland: mash: Convert TrayBackgroundView to wm common types

ash/system/tray/system_tray.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_SYSTEM_TRAY_SYSTEM_TRAY_H_
 #define ASH_SYSTEM_TRAY_SYSTEM_TRAY_H_
 
 #include <map>
 #include <memory>
 #include <vector>
 
 #include "ash/ash_export.h"
+#include "ash/common/system/tray/system_tray_bubble.h"
+#include "ash/common/system/tray/tray_background_view.h"
 #include "ash/system/cast/tray_cast.h"
-#include "ash/system/tray/system_tray_bubble.h"
-#include "ash/system/tray/tray_background_view.h"
 #include "ash/system/user/login_status.h"
-#include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
 #include "ui/views/bubble/tray_bubble_view.h"
 #include "ui/views/view.h"
 
 namespace ash {
 class ScreenTrayItem;
+class StatusAreaWidget;
 class SystemBubbleWrapper;
 class SystemTrayDelegate;
 class SystemTrayItem;
 class TrayAccessibility;
 class TrayDate;
 class TrayUpdate;
 class TrayUser;
 
 // There are different methods for creating bubble views.
 enum BubbleCreationType {
@@ skipping 171 matching lines @@
 
   // Records UMA metrics for the number of user-visible rows in the system menu
   // and the percentage of the work area height covered by the system menu.
   void RecordSystemMenuMetrics();
 
   const ScopedVector<SystemTrayItem>& items() const { return items_; }
 
   // Overridden from ActionableView.
   bool PerformAction(const ui::Event& event) override;
 
+  // The widget containing this view.
+  StatusAreaWidget* status_area_widget_;
+
   // Owned items.
   ScopedVector<SystemTrayItem> items_;
 
   // Pointers to members of |items_|.
   SystemTrayItem* detailed_item_;
   std::vector<SystemTrayItem*> notification_items_;
 
   // Mappings of system tray item and it's view in the tray.
   std::map<SystemTrayItem*, views::View*> tray_item_map_;
 
@@ skipping 24 matching lines @@
   // A reference to the Screen share and capture item.
   ScreenTrayItem* screen_capture_tray_item_;  // not owned
   ScreenTrayItem* screen_share_tray_item_;  // not owned
 
   DISALLOW_COPY_AND_ASSIGN(SystemTray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TRAY_SYSTEM_TRAY_H_