Implements \Drupal\Core\Form\FormInterface::submitForm().
Overrides FormInterface::submitForm
public function submitForm(array &$form, array &$form_state) {
// @todo Remove once http://drupal.org/node/1930274 is fixed.
aggregator_remove($this->feed);
$form_state['redirect'] = 'admin/config/services/aggregator';
}