No need to pass DownloadItemModel ownership.

chrome/browser/ui/gtk/download/download_shelf_gtk.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 CHROME_BROWSER_UI_GTK_DOWNLOAD_DOWNLOAD_SHELF_GTK_H_
 #define CHROME_BROWSER_UI_GTK_DOWNLOAD_DOWNLOAD_SHELF_GTK_H_
 
 #include <gtk/gtk.h>
 
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop.h"
 #include "chrome/browser/download/download_shelf.h"
 #include "chrome/browser/ui/gtk/slide_animator_gtk.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "ui/base/gtk/gtk_signal.h"
 #include "ui/base/gtk/owned_widget_gtk.h"
 #include "ui/gfx/native_widget_types.h"
 
 class Browser;
 class CustomDrawButton;
 class DownloadItemGtk;
-class DownloadItemModel;
 class GtkThemeService;
 
 namespace content {
 class PageNavigator;
 }
 
 namespace gfx {
 class Point;
 }
 
@@ skipping 24 matching lines @@
 
   // Returns the current height of the shelf.
   int GetHeight() const;
 
   // MessageLoop::Observer implementation:
   virtual void WillProcessEvent(GdkEvent* event) OVERRIDE;
   virtual void DidProcessEvent(GdkEvent* event) OVERRIDE;
 
  protected:
   // DownloadShelf implementation.
-  virtual void DoAddDownload(DownloadItemModel* download_model) OVERRIDE;
+  virtual void DoAddDownload(content::DownloadItem* download) OVERRIDE;
   virtual void DoShow() OVERRIDE;
   virtual void DoClose() OVERRIDE;
 
  private:
   // Remove |download_item| from the download shelf and delete it.
   void RemoveDownloadItem(DownloadItemGtk* download_item);
 
   // Get the hbox download items ought to pack themselves into.
   GtkWidget* GetHBox() const;
 
@@ skipping 69 matching lines @@
   // True if the mouse is within the shelf's bounds, as of the last mouse event
   // we received.
   bool mouse_in_shelf_;
 
   base::WeakPtrFactory<DownloadShelfGtk> weak_factory_;
 
   friend class DownloadItemGtk;
 };
 
 #endif  // CHROME_BROWSER_UI_GTK_DOWNLOAD_DOWNLOAD_SHELF_GTK_H_