RefCounted types should not have public destructors, chrome/browser/ part 5

chrome/browser/printing/cloud_print/virtual_driver_install_helper.h

 // Copyright (c) 2011 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_PRINTING_CLOUD_PRINT_VIRTUAL_DRIVER_INSTALL_HELPER_H_
 #define CHROME_BROWSER_PRINTING_CLOUD_PRINT_VIRTUAL_DRIVER_INSTALL_HELPER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 
 namespace cloud_print {
 
 // Helper class to register the Cloud Print Driver with the service process.
 class VirtualDriverInstallHelper
     : public base::RefCountedThreadSafe<VirtualDriverInstallHelper> {
  public:
   // Uses ServiceProcessControl to asynchronously get an instance
   // of the Service Process, launching it if necessary, and register
   // either InstallVirtualDriverTask or UninstallVirtualDriverTask as the
   // Task to be called once we have an instance of the ServiceProcess.
   static void SetUpInstall();
   static void SetUpUninstall();
 
  private:
+  friend class base::RefCountedThreadSafe<VirtualDriverInstallHelper>;
+
+  ~VirtualDriverInstallHelper() {}
+
   void InstallVirtualDriverTask();
   void UninstallVirtualDriverTask();
 };
 
 }  // namespace cloud_print
 
 #endif  // CHROME_BROWSER_PRINTING_CLOUD_PRINT_VIRTUAL_DRIVER_INSTALL_HELPER_H_