Performs end of request tasks.
@todo The body of this function has just been copied almost verbatim from drupal_page_footer(). There's probably a lot in here that needs to get removed/changed. Also, if possible, do more light-weight shutdowns on AJAX requests.
Symfony\Component\HttpKernel\Event\PostResponseEvent $event: The Event to process.
public function onTerminate(PostResponseEvent $event) {
module_invoke_all('exit');
module_implements_write_cache();
system_run_automated_cron();
}