DispatchEventResult EventDispatchMediator::dispatchEvent(
    EventDispatcher& dispatcher) const {
  DCHECK_EQ(m_event.get(), &dispatcher.event());
  return dispatcher.dispatch();
}
DispatchEventResult EventDispatchMediator::dispatchEvent(EventDispatcher& dispatcher) const
{
    ASSERT(m_event.get() == &dispatcher.event());
    return dispatcher.dispatch();
}