media: Make MediaKeys ref-counted.

media/cdm/default_cdm_factory.cc

 // Copyright 2014 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.
 
 #include "media/cdm/default_cdm_factory.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 25 matching lines @@
         FROM_HERE, base::Bind(cdm_created_cb, nullptr, "Invalid origin."));
     return;
   }
   if (!CanUseAesDecryptor(key_system)) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE,
         base::Bind(cdm_created_cb, nullptr, "Unsupported key system."));
     return;
   }
 
-  scoped_ptr<MediaKeys> cdm(
+  scoped_refptr<MediaKeys> cdm(
       new AesDecryptor(security_origin, session_message_cb, session_closed_cb,
                        session_keys_change_cb));
   base::ThreadTaskRunnerHandle::Get()->PostTask(
-      FROM_HERE, base::Bind(cdm_created_cb, base::Passed(&cdm), ""));
+      FROM_HERE, base::Bind(cdm_created_cb, cdm, ""));
 }
 
 }  // namespace media