No need to pass DownloadItemModel ownership.

chrome/browser/ui/views/download/download_shelf_context_menu_view.cc

 // Copyright (c) 2011 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 "chrome/browser/ui/views/download/download_shelf_context_menu_view.h"
 
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
 #include "chrome/browser/download/download_item_model.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/page_navigator.h"
 #include "ui/gfx/point.h"
 #include "ui/views/controls/menu/menu_item_view.h"
 #include "ui/views/controls/menu/menu_model_adapter.h"
 #include "ui/views/controls/menu/menu_runner.h"
 
 DownloadShelfContextMenuView::DownloadShelfContextMenuView(
-    DownloadItemModel* model,
+    content::DownloadItem* download_item,
     content::PageNavigator* navigator)
-    : DownloadShelfContextMenu(model, navigator) {
+    : DownloadShelfContextMenu(download_item, navigator) {
 }
 
 DownloadShelfContextMenuView::~DownloadShelfContextMenuView() {}
 
 void DownloadShelfContextMenuView::Run(views::Widget* parent_widget,
                                        const gfx::Rect& rect) {
-  views::MenuModelAdapter menu_model_adapter(GetMenuModel());
+  ui::MenuModel* menu_model = GetMenuModel();
+  // Run() should not be getting called if the DownloadItem was destroyed.
+  DCHECK(menu_model);
+
+  views::MenuModelAdapter menu_model_adapter(menu_model);
   menu_runner_.reset(new views::MenuRunner(menu_model_adapter.CreateMenu()));
 
   // The menu's alignment is determined based on the UI layout.
   views::MenuItemView::AnchorPosition position;
   if (base::i18n::IsRTL())
     position = views::MenuItemView::TOPRIGHT;
   else
     position = views::MenuItemView::TOPLEFT;
 
   // The return value of RunMenuAt indicates whether the MenuRunner was deleted
   // while running the menu, which indicates that the containing view may have
   // been deleted. We ignore the return value because our caller already assumes
   // that the view could be deleted by the time we return from here.
   ignore_result(menu_runner_->RunMenuAt(
       parent_widget,
       NULL,
       rect,
       position,
       views::MenuRunner::HAS_MNEMONICS | views::MenuRunner::CONTEXT_MENU));
 }