diff -u b/core/modules/block/src/BlockListBuilder.php b/core/modules/block/src/BlockListBuilder.php
--- b/core/modules/block/src/BlockListBuilder.php
+++ b/core/modules/block/src/BlockListBuilder.php
@@ -15,6 +15,7 @@
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Extension\ThemeHandlerInterface;
 use Drupal\Core\Form\FormBuilderInterface;
 use Drupal\Core\Form\FormInterface;
 use Drupal\Core\Form\FormStateInterface;
@@ -59,6 +60,13 @@
   protected $themeManager;
 
   /**
+   * The theme handler.
+   *
+   * @var \Drupal\Core\Extension\ThemeHandlerInterface
+   */
+  protected $themeHandler;
+
+  /**
    * The form builder.
    *
    * @var \Drupal\Core\Form\FormBuilderInterface
@@ -81,14 +89,17 @@
    *   The block manager.
    * @param \Drupal\Core\Theme\ThemeManagerInterface $theme_manager
    *   The theme manager.
+   * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
+   *   The theme manager.
    * @param \Drupal\Core\Form\FormBuilderInterface $form_builder
    *   The form builder.
    */
-  public function __construct(EntityTypeInterface $entity_type, EntityStorageInterface $storage, BlockManagerInterface $block_manager, ThemeManagerInterface $theme_manager, FormBuilderInterface $form_builder) {
+  public function __construct(EntityTypeInterface $entity_type, EntityStorageInterface $storage, BlockManagerInterface $block_manager, ThemeManagerInterface $theme_manager, ThemeHandlerInterface $theme_handler, FormBuilderInterface $form_builder) {
     parent::__construct($entity_type, $storage);
 
     $this->blockManager = $block_manager;
     $this->themeManager = $theme_manager;
+    $this->themeHandler = $theme_handler;
     $this->formBuilder = $form_builder;
   }
 
@@ -101,6 +112,7 @@
       $container->get('entity.manager')->getStorage($entity_type->id()),
       $container->get('plugin.manager.block'),
       $container->get('theme.manager'),
+      $container->get('theme_handler'),
       $container->get('form_builder')
     );
   }
@@ -141,6 +153,14 @@
     $form['#attached']['library'][] = 'block/drupal.block.admin';
     $form['#attributes']['class'][] = 'clearfix';
 
+    // Build the demonstrate block regions link.
+    $theme_info = $this->themeHandler->getTheme($this->getThemeName());
+    $form['demonstration_link'] = array(
+      '#type' => 'link',
+      '#title' => $this->t('Demonstrate block regions (@theme)', array('@theme' => $theme_info->info['name'])),
+      '#url' => Url::fromRoute('block.admin_demo', array('theme' => $this->theme)),
+    );
+
     // Build the form tree.
     $form['blocks'] = $this->buildBlocksForm();
     $form['place_blocks'] = $this->buildPlaceBlocksForm();
@@ -166,14 +186,6 @@
       '#type' => 'value',
       '#value' => $this->theme,
     );
-
-    $theme_info = \Drupal::service('theme_handler')->getTheme($this->theme);
-    $form['demonstration_link'] = array(
-      '#type' => 'link',
-      '#title' => $this->t('Demonstrate block regions (@theme)', array('@theme' => $theme_info->info['name'])),
-      '#url' => Url::fromRoute('block.admin_demo', array('theme' => $this->theme)),
-    );
-
     $form['blocks'] = array(
       '#type' => 'table',
       '#header' => array(
diff -u b/core/modules/block/templates/block-list.html.twig b/core/modules/block/templates/block-list.html.twig
--- b/core/modules/block/templates/block-list.html.twig
+++ b/core/modules/block/templates/block-list.html.twig
@@ -14,7 +14,7 @@
  */
 #}
 <div class="demonstration-block-link clearfix">
-    {{ form.demonstration_link }}
+  {{ form.demonstration_link }}
 </div>
 <div class="layout-block-list clearfix">
   <div class="layout-region block-list-primary">