diff --git c/core/modules/system/tests/modules/theme_test/lib/Drupal/theme_test/ThemeTestController.php w/core/modules/system/tests/modules/theme_test/lib/Drupal/theme_test/ThemeTestController.php
index 426c4cb..df84ed5 100644
--- c/core/modules/system/tests/modules/theme_test/lib/Drupal/theme_test/ThemeTestController.php
+++ w/core/modules/system/tests/modules/theme_test/lib/Drupal/theme_test/ThemeTestController.php
@@ -7,25 +7,15 @@
 
 namespace Drupal\theme_test;
 
-use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
-
 /**
  * Controller routines for theme test routes.
  */
-class ThemeTestController implements ContainerInjectionInterface {
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function create(ContainerInterface $container) {
-    return new static();
-  }
+class ThemeTestController {
 
   /**
    * Menu callback for testing that a theme template overrides a theme function.
    */
-  function functionTemplateOverridden() {
+  public function functionTemplateOverridden() {
     return array(
       '#theme' => 'theme_test_function_template_override',
     );
@@ -34,7 +24,7 @@ function functionTemplateOverridden() {
   /**
    * Calls a theme hook suggestion.
    */
-  function themeTestSuggestion() {
+  public function themeTestSuggestion() {
     return theme(array('theme_test__suggestion', 'theme_test'), array());
   }
 }