Revert 149794 - DownloadItem::Observer::OnDownloadDestroyed() replaces DownloadItem::REMOVING

chrome/browser/plugin_installer.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_PLUGIN_INSTALLER_H_
 #define CHROME_BROWSER_PLUGIN_INSTALLER_H_
 
 #include "base/observer_list.h"
 #include "base/string16.h"
 #include "base/version.h"
@@ skipping 30 matching lines @@
   };
 
   PluginInstaller(const std::string& identifier,
                   const string16& name,
                   bool url_for_display,
                   const GURL& plugin_url,
                   const GURL& help_url);
   virtual ~PluginInstaller();
 
   virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
-  virtual void OnDownloadDestroyed(content::DownloadItem* download) OVERRIDE;
+
+  virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE;
 
   void AddObserver(PluginInstallerObserver* observer);
   void RemoveObserver(PluginInstallerObserver* observer);
 
   void AddWeakObserver(WeakPluginInstallerObserver* observer);
   void RemoveWeakObserver(WeakPluginInstallerObserver* observer);
 
   // Unique identifier for the plug-in.
   const std::string& identifier() const { return identifier_; }
 
@@ skipping 52 matching lines @@
   std::map<Version, SecurityStatus, VersionComparator> versions_;
 
   InstallerState state_;
   ObserverList<PluginInstallerObserver> observers_;
   ObserverList<WeakPluginInstallerObserver> weak_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginInstaller);
 };
 
 #endif  // CHROME_BROWSER_PLUGIN_INSTALLER_H_