Make DownloadHistory observe manager, items

chrome/browser/ui/gtk/download/download_item_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_ITEM_GTK_H_
 #define CHROME_BROWSER_UI_GTK_DOWNLOAD_DOWNLOAD_ITEM_GTK_H_
 
 #include <gtk/gtk.h>
 
 #include <string>
@@ skipping 32 matching lines @@
  public:
   // DownloadItemGtk takes ownership of |download_item_model|.
   DownloadItemGtk(DownloadShelfGtk* parent_shelf,
                   BaseDownloadItemModel* download_item_model);
 
   // Destroys all widgets belonging to this DownloadItemGtk.
   virtual ~DownloadItemGtk();
 
   // content::DownloadItem::Observer implementation.
   virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
+  virtual void OnDownloadDestroyed(content::DownloadItem* download) OVERRIDE;
   virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE;
 
   // ui::AnimationDelegate implementation.
   virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
 
   // Overridden from content::NotificationObserver:
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
@@ skipping 180 matching lines @@
 
   // Whether we are currently disabled as part of opening the downloaded file.
   bool disabled_while_opening_;
 
   // Method factory used to delay reenabling of the item when opening the
   // downloaded file.
   base::WeakPtrFactory<DownloadItemGtk> weak_ptr_factory_;
 };
 
 #endif  // CHROME_BROWSER_UI_GTK_DOWNLOAD_DOWNLOAD_ITEM_GTK_H_