Issue #3292076: Move additional cache values out of UI module and into base.

modules/purge_ui/purge_ui.module

@@ -5,8 +5,6 @@
  * Administrative interface for Purge.
  */
 
-use Drupal\Core\Form\FormStateInterface;
-
 /**
  * Implements hook_theme().
  */
@@ -22,15 +20,3 @@ function purge_ui_theme() {
     ],
   ];
 }
-
-/**
- * Implements hook_form_FORM_ID_alter().
- *
- * Add some serious options to the page_cache_maximum_age setting.
- */
-function purge_ui_form_system_performance_settings_alter(&$form, FormStateInterface $form_state, $form_id) {
-  $form['caching']['page_cache_maximum_age']['#options'][604800] = t("1 week");
-  $form['caching']['page_cache_maximum_age']['#options'][2764800] = t("1 month");
-  $form['caching']['page_cache_maximum_age']['#options'][16588800] = t("6 months");
-  $form['caching']['page_cache_maximum_age']['#options'][31536000] = t("1 year (recommended for external cache invalidation)");
-}