Fixes possible crash in closing menus. Specifically if we Close a

ui/views/controls/menu/menu_host.cc

 // 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.
 
 #include "ui/views/controls/menu/menu_host.h"
 
 #include "ui/views/controls/menu/menu_controller.h"
 #include "ui/views/controls/menu/menu_host_root_view.h"
 #include "ui/views/controls/menu/menu_item_view.h"
 #include "ui/views/controls/menu/native_menu_host.h"
@@ skipping 91 matching lines @@
   if (!destroying_) {
     // We weren't explicitly told to destroy ourselves, which means the menu was
     // deleted out from under us (the window we're parented to was closed). Tell
     // the SubmenuView to drop references to us.
     submenu_->MenuHostDestroyed();
   }
   Widget::OnNativeWidgetDestroyed();
 }
 
 void MenuHost::OnOwnerClosing() {
+  if (destroying_)
+    return;
+
   MenuController* menu_controller =
       submenu_->GetMenuItem()->GetMenuController();
   if (menu_controller && !menu_controller->drag_in_progress())
     menu_controller->CancelAll();
 }
 
 }  // namespace views