Extend scoped_ptr to be closer to unique_ptr. Support custom deleters, and deleting arrays.

media/base/message_loop_factory.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 MEDIA_BASE_MESSAGE_LOOP_FACTORY_H_
 #define MEDIA_BASE_MESSAGE_LOOP_FACTORY_H_
 
 #include <list>
 #include <string>
 
@@ skipping 20 matching lines @@
     kPipeline
   };
 
   MessageLoopFactory();
 
   // Get the message loop proxy associated with |type|. A new MessageLoopProxy
   // is created if the factory doesn't have one associated with |type|.
   scoped_refptr<base::MessageLoopProxy> GetMessageLoop(Type type);
 
  private:
-  // Only allow scoped_ptr<> to delete factory.
-  friend class scoped_ptr<MessageLoopFactory>;
+  // Restrict who can delete the factory to scoped_ptr<>. scoped_ptr<> uses
+  // base::DefaultDeleter.
+  friend struct base::DefaultDeleter<MessageLoopFactory>;
   ~MessageLoopFactory();
 
   // Returns the thread associated with |type| creating a new thread if needed.
   base::Thread* GetThread(Type type);
 
   // Lock used to serialize access for the following data members.
   base::Lock lock_;
 
   // List of pairs of created threads and their types.  We use a list to ensure
   // threads are stopped & deleted in reverse order of creation.
   typedef std::list<std::pair<Type, base::Thread*> > ThreadList;
   ThreadList threads_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageLoopFactory);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MESSAGE_LOOP_FACTORY_H_