First patch in making destructors of refcounted objects private.

base/ref_counted.h

 // Copyright (c) 2006-2008 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_REF_COUNTED_H_
 #define BASE_REF_COUNTED_H_
 
 #include "base/atomic_ref_count.h"
 #include "base/thread_collision_warner.h"
 
@@ skipping 53 matching lines @@
 
 }  // namespace subtle
 
 //
 // A base class for reference counted classes.  Otherwise, known as a cheap
 // knock-off of WebKit's RefCounted<T> class.  To use this guy just extend your
 // class from it like so:
 //
 //   class MyFoo : public base::RefCounted<MyFoo> {
 //    ...
+//    private:
+//     friend class base::RefCounted<MyFoo>;
+//     ~MyFoo();
 //   };
 //
+// You should always make your destructor private, to avoid any code deleting
+// the object accidently while there are references to it.
 template <class T>
 class RefCounted : public subtle::RefCountedBase {
  public:
   RefCounted() { }
   ~RefCounted() { }
 
   void AddRef() {
     subtle::RefCountedBase::AddRef();
   }
 
@@ skipping 22 matching lines @@
   }
 };
 
 //
 // A thread-safe variant of RefCounted<T>
 //
 //   class MyFoo : public base::RefCountedThreadSafe<MyFoo> {
 //    ...
 //   };
 //
-// If you're using the default trait, then you may choose to add compile time
+// If you're using the default trait, then you should add compile time
 // asserts that no one else is deleting your object.  i.e.
 //    private:
-//     friend struct base::RefCountedThreadSafe<MyFoo>;
+//     friend class base::RefCountedThreadSafe<MyFoo>;
 //     ~MyFoo();
 template <class T, typename Traits = DefaultRefCountedThreadSafeTraits<T> >
 class RefCountedThreadSafe : public subtle::RefCountedThreadSafeBase {
  public:
   RefCountedThreadSafe() { }
   ~RefCountedThreadSafe() { }
 
   void AddRef() {
     subtle::RefCountedThreadSafeBase::AddRef();
   }
@@ skipping 132 matching lines @@
 
   void swap(scoped_refptr<T>& r) {
     swap(&r.ptr_);
   }
 
  protected:
   T* ptr_;
 };
 
 #endif  // BASE_REF_COUNTED_H_