RefCounted types should not have public destructors

base/memory/ref_counted.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 BASE_MEMORY_REF_COUNTED_H_
 #define BASE_MEMORY_REF_COUNTED_H_
 #pragma once
 
 #include <cassert>
 
@@ skipping 146 matching lines @@
 // A wrapper for some piece of data so we can place other things in
 // scoped_refptrs<>.
 //
 template<typename T>
 class RefCountedData : public base::RefCounted< base::RefCountedData<T> > {
  public:
   RefCountedData() : data() {}
   RefCountedData(const T& in_value) : data(in_value) {}
 
   T data;
+
+ private:
+  friend class base::RefCounted<base::RefCountedData<T> >;
+  ~RefCountedData() {}
 };
 
 }  // namespace base
 
 //
 // A smart pointer class for reference counted objects.  Use this class instead
 // of calling AddRef and Release manually on a reference counted object to
 // avoid common memory leaks caused by forgetting to Release an object
 // reference.  Sample usage:
 //
@@ skipping 121 matching lines @@
 };
 
 // Handy utility for creating a scoped_refptr<T> out of a T* explicitly without
 // having to retype all the template arguments
 template <typename T>
 scoped_refptr<T> make_scoped_refptr(T* t) {
   return scoped_refptr<T>(t);
 }
 
 #endif  // BASE_MEMORY_REF_COUNTED_H_