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

chrome/browser/profiles/refcounted_profile_keyed_service.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_PROFILES_REFCOUNTED_PROFILE_KEYED_SERVICE_H_
 #define CHROME_BROWSER_PROFILES_REFCOUNTED_PROFILE_KEYED_SERVICE_H_
 
 #include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner_helpers.h"
 #include "content/public/browser/browser_thread.h"
 
 class RefcountedProfileKeyedService;
 
 namespace impl {
 
 struct RefcountedProfileKeyedServiceTraits {
   static void Destruct(const RefcountedProfileKeyedService* obj);
 };
 
@@ skipping 16 matching lines @@
           RefcountedProfileKeyedService,
           impl::RefcountedProfileKeyedServiceTraits> {
  public:
   // Unlike ProfileKeyedService, ShutdownOnUI is not optional. You must do
   // something to drop references during the first pass Shutdown() because this
   // is the only point where you are guaranteed that something is running on
   // the UI thread. The PKSF framework will ensure that this is only called on
   // the UI thread; you do not need to check for that yourself.
   virtual void ShutdownOnUIThread() = 0;
 
-  // The second pass destruction can happen anywhere unless you specify which
-  // thread this service must be destroyed on by using the second constructor.
-  virtual ~RefcountedProfileKeyedService();
-
  protected:
   // If your service does not need to be deleted on a specific thread, use the
   // default constructor.
   RefcountedProfileKeyedService();
 
   // If you need your service to be deleted on a specific thread (for example,
   // you're converting a service that used content::DeleteOnThread<IO>), then
   // use this constructor with the ID of the thread.
   explicit RefcountedProfileKeyedService(
       const content::BrowserThread::ID thread_id);
 
+  // The second pass destruction can happen anywhere unless you specify which
+  // thread this service must be destroyed on by using the second constructor.
+  virtual ~RefcountedProfileKeyedService();
+
  private:
   friend struct impl::RefcountedProfileKeyedServiceTraits;
+  friend class base::DeleteHelper<RefcountedProfileKeyedService>;
 
   // Do we have to delete this object on a specific thread?
   bool requires_destruction_on_thread_;
   content::BrowserThread::ID thread_id_;
 };
 
 #endif  // CHROME_BROWSER_PROFILES_REFCOUNTED_PROFILE_KEYED_SERVICE_H_