Allow menus to stay open during a child view's drag and drop

ui/views/controls/menu/menu_delegate.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 UI_VIEWS_CONTROLS_MENU_MENU_DELEGATE_H_
 #define UI_VIEWS_CONTROLS_MENU_MENU_DELEGATE_H_
 
 #include <set>
 #include <string>
 
@@ skipping 190 matching lines @@
 
   // Invoked to determine the drag operations for a drag session of sender.
   // See DragDropTypes for possible values.
   virtual int GetDragOperations(MenuItemView* sender);
 
   // Notification the menu has closed. This is only sent when running the
   // menu for a drop.
   virtual void DropMenuClosed(MenuItemView* menu) {
   }
 
+  // Returns true if the menu should close upon a drag completing. Defaults to
+  // true. This is only invoked for drag and drop operations performed on child
+  // Views that are not MenuItemViews.
+  virtual bool ShouldCloseOnDragComplete();
+
   // Notification that the user has highlighted the specified item.
   virtual void SelectionChanged(MenuItemView* menu) {
   }
 
   // If the user drags the mouse outside the bounds of the menu the delegate
   // is queried for a sibling menu to show. If this returns non-null the
   // current menu is hidden, and the menu returned from this method is shown.
   //
   // The delegate owns the returned menu, not the controller.
   virtual MenuItemView* GetSiblingMenu(MenuItemView* menu,
@@ skipping 20 matching lines @@
                                         int* left_margin,
                                         int* right_margin) const;
   // Returns true if the labels should reserve additional spacing for e.g.
   // submenu indicators at the end of the line.
   virtual bool ShouldReserveSpaceForSubmenuIndicator() const;
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_MENU_MENU_DELEGATE_H_