Make IDL Callbacks non-refcounted by default

Source/modules/webmidi/MIDIAccessPromise.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 81 matching lines @@
             m_state = Invoked;
             m_errorCallback->handleEvent(error.get());
             clear();
         } else {
             m_state = Rejected;
             m_error = error;
         }
     }
 }
 
-void MIDIAccessPromise::then(PassRefPtr<MIDISuccessCallback> successCallback, PassRefPtr<MIDIErrorCallback> errorCallback)
+void MIDIAccessPromise::then(PassOwnPtr<MIDISuccessCallback> successCallback, PassOwnPtr<MIDIErrorCallback> errorCallback)
 {
     // Lazily request access.
     if (!m_access)
         m_access = MIDIAccess::create(executionContext(), this);
 
     switch (m_state) {
     case Accepted:
         m_state = Invoked;
         successCallback->handleEvent(m_access.get(), m_options->sysex);
         clear();
@@ skipping 18 matching lines @@
 {
     ASSERT(m_state == Invoked);
     m_access.clear();
     m_error.clear();
     m_options.clear();
     m_successCallback.clear();
     m_errorCallback.clear();
 }
 
 } // namespace WebCore