RefCounted types should not have public destructors, chrome/browser/extensions

chrome/browser/extensions/webstore_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_EXTENSIONS_WEBSTORE_INSTALLER_H_
 #define CHROME_BROWSER_EXTENSIONS_WEBSTORE_INSTALLER_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 71 matching lines @@
   // use the specified |controller| to download the extension. Only one
   // WebstoreInstaller can use a specific controller at any given time. This
   // also associates the |approval| with this install.
   // Note: the delegate should stay alive until being called back.
   WebstoreInstaller(Profile* profile,
                     Delegate* delegate,
                     content::NavigationController* controller,
                     const std::string& id,
                     scoped_ptr<Approval> approval,
                     int flags);
-  virtual ~WebstoreInstaller();
 
   // Starts downloading and installing the extension.
   void Start();
 
   // content::NotificationObserver
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
   // Instead of using the default download directory, use |directory| instead.
   // This does *not* transfer ownership of |directory|.
   static void SetDownloadDirectoryForTests(FilePath* directory);
 
  private:
+  friend class base::RefCounted<WebstoreInstaller>;
+  virtual ~WebstoreInstaller();
+
   // DownloadManager::DownloadUrl callback.
   void OnDownloadStarted(content::DownloadId id, net::Error error);
 
   // DownloadItem::Observer implementation:
   virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
   virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE;
 
   // Starts downloading the extension to |file_path|.
   void StartDownload(const FilePath& file_path);
 
@@ skipping 14 matching lines @@
   // The DownloadItem is owned by the DownloadManager and is valid from when
   // OnDownloadStarted is called (with no error) until the DownloadItem
   // transitions to state REMOVING.
   content::DownloadItem* download_item_;
   int flags_;
   scoped_ptr<Approval> approval_;
   GURL download_url_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_WEBSTORE_INSTALLER_H_