Reland DownloadItem::Observer::OnDownloadDestroyed() replaces DownloadItem::REMOVING

chrome/browser/chromeos/gdata/gdata_download_observer.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_CHROMEOS_GDATA_GDATA_DOWNLOAD_OBSERVER_H__
 #define CHROME_BROWSER_CHROMEOS_GDATA_GDATA_DOWNLOAD_OBSERVER_H__
 #pragma once
 
 #include <map>
 
@@ skipping 71 matching lines @@
   static void GetGDataTempDownloadPath(const FilePath& gdata_tmp_download_dir,
                                        FilePath* gdata_tmp_download_path);
 
  private:
   // DownloadManager overrides.
   virtual void ManagerGoingDown(content::DownloadManager* manager) OVERRIDE;
   virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
 
   // DownloadItem overrides.
   virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
-  virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE {}
+  virtual void OnDownloadDestructed(content::DownloadItem* download) OVERRIDE;
 
   // Adds/Removes |download| to pending_downloads_.
   // Also start/stop observing |download|.
   void AddPendingDownload(content::DownloadItem* download);
   void RemovePendingDownload(content::DownloadItem* download);
 
   // Remove our external data and remove our observers from |download|
   void DetachFromDownload(content::DownloadItem* download);
 
   // Starts the upload of a downloaded/downloading file.
@@ skipping 31 matching lines @@
   DownloadMap pending_downloads_;
 
   base::WeakPtrFactory<GDataDownloadObserver> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GDataDownloadObserver);
 };
 
 }  // namespace gdata
 
 #endif  // CHROME_BROWSER_CHROMEOS_GDATA_GDATA_DOWNLOAD_OBSERVER_H__