[ash] Add TYPE_DIALOG and its item's LauncherContextMenu

ash/shelf/shelf_item_delegate.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_SHELF_SHELF_ITEM_DELEGATE_H_
 #define ASH_SHELF_SHELF_ITEM_DELEGATE_H_
 
 #include "ash/ash_export.h"
 #include "base/strings/string16.h"
 
@@ skipping 41 matching lines @@
   //  - A list containing the title and the active list of items.
   // The caller takes ownership of the returned model.
   // |event_flags| specifies the flags of the event which triggered this menu.
   virtual ShelfMenuModel* CreateApplicationMenu(int event_flags) = 0;
 
   // Whether the launcher item is draggable.
   virtual bool IsDraggable() = 0;
 
   // Returns true if a tooltip should be shown.
   virtual bool ShouldShowTooltip() = 0;
+
+  // Closes all windows associated with this item.
+  virtual void Close() = 0;
+
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_ITEM_DELEGATE_H_