diff -u b/core/lib/Drupal/Core/Render/Element/SystemCompactLink.php b/core/lib/Drupal/Core/Render/Element/SystemCompactLink.php
--- b/core/lib/Drupal/Core/Render/Element/SystemCompactLink.php
+++ b/core/lib/Drupal/Core/Render/Element/SystemCompactLink.php
@@ -7,6 +7,9 @@
 
 namespace Drupal\Core\Render\Element;
 
+use Drupal\Core\Url;
+use Drupal\Component\Utility\NestedArray;
+
 /**
  * Provides a link render element to show or hide inline help descriptions.
  *
@@ -38,14 +41,14 @@
    * Doing so during pre_render gives modules a chance to alter the link parts.
    *
    * @param array $element
-   *   A structured array whose keys form the arguments to l():
-   *   - #title: The link text to pass as argument to l().
+   *   A structured array whose keys form the arguments to Drupal::l():
+   *   - #title: The link text to pass as argument to Drupal::l().
    *   - One of the following:
    *     - #route_name and (optionally) a #route_parameters array; The route
    *       name and route parameters which will be passed into the link
    *       generator.
-   *     - #href: The system path or URL to pass as argument to l().
-   *   - #options: (optional) An array of options to pass to l() or the link
+   *     - #href: The system path or URL to pass as argument to Drupal::l().
+   *   - #options: (optional) An array of options to pass to Drupal::l() or the link
    *     generator.
    *
    * @return array
@@ -56,23 +59,25 @@
     $element += array('#options' => array());
 
     if (system_admin_compact_mode()) {
-      $element['#title'] = t('Show descriptions');
-      $element['#route_name'] = 'system.admin_compact_page';
-      $element['#route_parameters'] = array('mode' => 'off');
+      $element['#title'] = \Drupal::translation()->translate('Show descriptions');
+      $element['#url'] = Url::fromRoute('system.admin_compact_page', array('mode' => 'off'));
       $element['#options'] = array(
-        'attributes' => array('title' => t('Expand layout to include descriptions.')),
+        'attributes' => array('title' => \Drupal::translation()->translate('Expand layout to include descriptions.')),
         'query' => drupal_get_destination(),
       );
     }
     else {
-      $element['#title'] = t('Hide descriptions');
-      $element['#route_name'] = 'system.admin_compact_page';
-      $element['#route_parameters'] = array('mode' => 'on');
+      $element['#title'] = \Drupal::translation()->translate('Hide descriptions');
+      $element['#url'] = Url::fromRoute('system.admin_compact_page', array('mode' => 'on'));
       $element['#options'] = array(
-        'attributes' => array('title' => t('Compress layout by hiding descriptions.')),
+        'attributes' => array('title' => \Drupal::translation()->translate('Compress layout by hiding descriptions.')),
         'query' => drupal_get_destination(),
       );
     }
+
+    $options = NestedArray::mergeDeep($element['#url']->getOptions(), $element['#options']);
+    $element['#markup'] = \Drupal::l($element['#title'], $element['#url']->setOptions($options));
+
     return $element;
   }
 
diff -u b/core/modules/system/css/system.admin.css b/core/modules/system/css/system.admin.css
--- b/core/modules/system/css/system.admin.css
+++ b/core/modules/system/css/system.admin.css
@@ -28,7 +28,7 @@
 }
 
 /**
- * System compact link: to toggle the display of description text.
+ * Markup generated by theme_system_compact_link().
  */
 .compact-link {
   margin: 0 0 0.5em 0;
@@ -69,7 +69,7 @@
 }
 
 /**
- * Markup generated by theme_system_compact_link().
+ * System compact link: to toggle the display of description text.
  */
 .compact-link {
   margin: 0 0 0.5em 0;
diff -u b/core/modules/system/system.module b/core/modules/system/system.module
--- b/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -209,14 +209,13 @@
       'variables' => array('menu_items' => NULL),
       'file' => 'system.admin.inc',
     ),
-    'system_compact_link' => array(
-      'variables' => array(),
-      'function' => 'theme_system_compact_link',
-    ),
   ));
 }
 
     ),
+    'system_compact_link' => array(
+      'variables' => array(),
+    ),
   ));
 }
 
only in patch2:
unchanged:
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -2994,6 +2994,7 @@ function drupal_render(&$elements, $is_root_call = FALSE) {
 
   $elements['#printed'] = TRUE;
   $elements['#markup'] = SafeMarkup::set($elements['#markup']);
+
   return $elements['#markup'];
 }