diff --git a/core/modules/system/tests/modules/ajax_test/ajax_test.module b/core/modules/system/tests/modules/ajax_test/ajax_test.module
index 2ea9eb9..2f6a7d9 100644
--- a/core/modules/system/tests/modules/ajax_test/ajax_test.module
+++ b/core/modules/system/tests/modules/ajax_test/ajax_test.module
@@ -21,176 +21,6 @@ function ajax_test_system_theme_info() {
 }
 
 /**
- * Menu callback: Returns an element suitable for use by ajax_render().
- *
- * Additionally ensures that ajax_render() incorporates JavaScript settings
- * generated during the page request by invoking _drupal_add_js() with a dummy
- * setting.
- *
- * @deprecated \Drupal\ajax_test\Controller\AjaxTestController::render()
- */
-function ajax_test_render() {
-  $attached = array(
-    '#attached' => array(
-      'js' => array(
-        0 => array(
-          'type' => 'setting',
-          'data' => array('ajax' => 'test'),
-        ),
-      ),
-    ),
-  );
-  drupal_render($attached);
-  $response = new AjaxResponse();
-  return $response;
-}
-
-/**
- * Menu callback: Returns an AjaxResponse; settings command set last.
- *
- * Helps verifying AjaxResponse reorders commands to ensure correct execution.
- *
- * @deprecated \Drupal\ajax_test\Controller\AjaxTestController::order()
- */
-function ajax_test_order() {
-  $response = new AjaxResponse();
-  $path = drupal_get_path('module', 'system');
-  // HTML insertion command.
-  $response->addCommand(new HtmlCommand('body', 'Hello, world!'));
-  $attached = array(
-    '#attached' => array(
-      'css' => array(
-        // Add two CSS files (order should remain the same).
-        $path . '/css/system.admin.css' => array(),
-        $path . '/css/system.maintenance.css' => array(),
-      ),
-      'js' => array(
-        // Add two JavaScript files (first to the footer, should appear last).
-        $path . '/system.modules.js' => array('scope' => 'footer'),
-        $path . '/system.js' => array(),
-        // Finally, add a JavaScript setting.
-        0 => array(
-          'type' => 'setting',
-          'data' => array('ajax' => 'test'),
-        ),
-      ),
-    ),
-  );
-  drupal_render($attached);
-  return $response;
-}
-
-/**
- * Menu callback: Returns AJAX element with #error property set.
- *
- * @deprecated \Drupal\ajax_test\Controller\AjaxTestController::renderError()
- */
-function ajax_test_error() {
-  $message = '';
-  $query = \Drupal::request()->query;
-  if ($query->has('message')) {
-    $message = $query->get('message');
-  }
-  $response = new AjaxResponse();
-  $response->addCommand(new AlertCommand($message));
-  return $response;
-}
-
-/**
- * Menu callback: Renders a form elements and links with #ajax['dialog'].
- *
- * @deprecated \Drupal\ajax_test\Controller\AjaxTestController::dialog()
- */
-function ajax_test_dialog() {
-  // Add two wrapper elements for testing non-modal dialogs. Modal dialogs use
-  // the global drupal-modal wrapper by default.
-  $build['dialog_wrappers'] = array('#markup' => '<div id="ajax-test-dialog-wrapper-1"></div><div id="ajax-test-dialog-wrapper-2"></div>');
-
-  // Dialog behavior applied to a button.
-  $build['form'] = drupal_get_form('ajax_test_dialog_form');
-
-  // Dialog behavior applied to a #type => 'link'.
-  $build['link'] = array(
-    '#type' => 'link',
-    '#title' => 'Link 1 (modal)',
-    '#href' => 'ajax-test/dialog-contents',
-    '#attributes' => array(
-      'class' => array('use-ajax'),
-      'data-accepts' => 'application/vnd.drupal-modal',
-    ),
-  );
-
-  // Dialog behavior applied to links rendered by theme_links().
-  $build['links'] = array(
-    '#theme' => 'links',
-    '#links' => array(
-      'link2' => array(
-        'title' => 'Link 2 (modal)',
-        'href' => 'ajax-test/dialog-contents',
-        'attributes' => array(
-          'class' => array('use-ajax'),
-          'data-accepts' => 'application/vnd.drupal-modal',
-          'data-dialog-options' => json_encode(array(
-            'width' => 400,
-          ))
-        ),
-      ),
-      'link3' => array(
-        'title' => 'Link 3 (non-modal)',
-        'href' => 'ajax-test/dialog-contents',
-        'attributes' => array(
-          'class' => array('use-ajax'),
-          'data-accepts' => 'application/vnd.drupal-dialog',
-          'data-dialog-options' => json_encode(array(
-            'target' => 'ajax-test-dialog-wrapper-1',
-            'width' => 800,
-          ))
-        ),
-      ),
-      'link4' => array(
-        'title' => 'Link 4 (close non-modal if open)',
-        'href' => 'ajax-test/dialog-close',
-        'attributes' => array(
-          'class' => array('use-ajax'),
-        ),
-      ),
-      'link5' => array(
-        'title' => 'Link 5 (form)',
-        'href' => 'ajax-test/dialog-form',
-        'attributes' => array(
-          'class' => array('use-ajax'),
-          'data-accepts' => 'application/vnd.drupal-modal',
-        ),
-      ),
-      'link6' => array(
-        'title' => 'Link 6 (entity form)',
-        'href' => 'admin/structure/contact/add',
-        'attributes' => array(
-          'class' => array('use-ajax'),
-          'data-accepts' => 'application/vnd.drupal-modal',
-          'data-dialog-options' => json_encode(array(
-            'width' => 800,
-            'height' => 500,
-          ))
-        ),
-      ),
-      'link7' => array(
-        'title' => 'Link 7 (non-modal, no target)',
-        'href' => 'ajax-test/dialog-contents',
-        'attributes' => array(
-          'class' => array('use-ajax'),
-          'data-accepts' => 'application/vnd.drupal-dialog',
-          'data-dialog-options' => json_encode(array(
-            'width' => 800,
-          ))
-        ),
-      ),
-    ),
-  );
-  return $build;
-}
-
-/**
  * Form builder: Renders buttons with #ajax['dialog'].
  */
 function ajax_test_dialog_form($form, &$form_state) {
@@ -284,14 +114,3 @@ function ajax_test_dialog_contents() {
 
   return $content;
 }
-
-/**
- * Menu callback: Close the ajax dialog.
- *
- * @deprecated \Drupal\ajax_test\Controller\AjaxTestController::dialogClose()
- */
-function ajax_test_dialog_close() {
-  $response = new AjaxResponse();
-  $response->addCommand(new CloseDialogCommand('#ajax-test-dialog-wrapper-1'));
-  return $response;
-}
diff --git a/core/modules/system/tests/modules/ajax_test/lib/Drupal/ajax_test/Controller/AjaxTestController.php b/core/modules/system/tests/modules/ajax_test/lib/Drupal/ajax_test/Controller/AjaxTestController.php
index b6d5be0..a775983 100644
--- a/core/modules/system/tests/modules/ajax_test/lib/Drupal/ajax_test/Controller/AjaxTestController.php
+++ b/core/modules/system/tests/modules/ajax_test/lib/Drupal/ajax_test/Controller/AjaxTestController.php
@@ -7,6 +7,12 @@
 
 namespace Drupal\ajax_test\Controller;
 
+use Drupal\Core\Ajax\AddCssCommand;
+use Drupal\Core\Ajax\AjaxResponse;
+use Drupal\Core\Ajax\HtmlCommand;
+use Drupal\Core\Ajax\SettingsCommand;
+use Symfony\Component\HttpFoundation\Request;
+
 /**
  * Provides content for dialog tests.
  */
@@ -24,35 +30,152 @@ public function dialogContents() {
    * @todo Remove ajax_test_render().
    */
   public function render() {
-    return ajax_test_render();
+   $response = new AjaxResponse();
+   $response->addCommand(new SettingsCommand(array('ajax' => 'test')));
+   return $response;
   }
 
   /**
-   * @todo Remove ajax_test_order().
+   * Helps verifying AjaxResponse reorders commands to ensure correct execution.
    */
   public function order() {
-    return ajax_test_order();
+      $response = new AjaxResponse();
+      $path = drupal_get_path('module', 'system');
+      $build = array();
+
+      // HTML insertion command.
+      $build['content'] = array(
+        '#type' => 'markup',
+        '#markup' => 'Hello, world!',
+      );
+      // Add two CSS files (order should remain the same).
+      $build['#attached']['css'] = array(
+        $path . '/css/system.admin.css',
+        $path . '/css/system.maintenance.css',
+      );
+      // Add two JavaScript files (first to the footer, should appear last).
+      $build['#attached']['js'] = array(
+        $path . '/system.modules.js',
+        $path . '/system.js',
+      );
+      $response->addCommand(new HtmlCommand('body', $build));
+      // Finally, add a JavaScript setting.
+      $response->addCommand(new SettingsCommand(array('ajax' => 'test')));
+      return $response;
   }
 
   /**
-   * @todo Remove ajax_test_error().
+   * Returns AJAX element with #error property set.
    */
-  public function renderError() {
-    return ajax_test_error();
+  public function renderError(Request $request) {
+    $message = '';
+    if ($request->query->has('message')) {
+      $message = $request->query->get('message');
+    }
+    $response = new AjaxResponse();
+    $response->addCommand(new AlertCommand($message));
+    return $response;
   }
 
   /**
    * @todo Remove ajax_test_dialog().
    */
   public function dialog() {
-    return ajax_test_dialog();
+    // Add two wrapper elements for testing non-modal dialogs. Modal dialogs use
+    // the global drupal-modal wrapper by default.
+    $build['dialog_wrappers'] = array('#markup' => '<div id="ajax-test-dialog-wrapper-1"></div><div id="ajax-test-dialog-wrapper-2"></div>');
+
+    // Dialog behavior applied to a button.
+    $build['form'] = \Drupal::formBuilder()->getForm('ajax_test_dialog_form');
+
+    // Dialog behavior applied to a #type => 'link'.
+    $build['link'] = array(
+      '#type' => 'link',
+      '#title' => 'Link 1 (modal)',
+      '#href' => 'ajax-test/dialog-contents',
+      '#attributes' => array(
+        'class' => array('use-ajax'),
+        'data-accepts' => 'application/vnd.drupal-modal',
+      ),
+    );
+
+    // Dialog behavior applied to links rendered by theme_links().
+    $build['links'] = array(
+      '#theme' => 'links',
+      '#links' => array(
+        'link2' => array(
+          'title' => 'Link 2 (modal)',
+          'href' => 'ajax-test/dialog-contents',
+          'attributes' => array(
+            'class' => array('use-ajax'),
+            'data-accepts' => 'application/vnd.drupal-modal',
+            'data-dialog-options' => json_encode(array(
+              'width' => 400,
+            ))
+          ),
+        ),
+        'link3' => array(
+          'title' => 'Link 3 (non-modal)',
+          'href' => 'ajax-test/dialog-contents',
+          'attributes' => array(
+            'class' => array('use-ajax'),
+            'data-accepts' => 'application/vnd.drupal-dialog',
+            'data-dialog-options' => json_encode(array(
+              'target' => 'ajax-test-dialog-wrapper-1',
+              'width' => 800,
+            ))
+          ),
+        ),
+        'link4' => array(
+          'title' => 'Link 4 (close non-modal if open)',
+          'href' => 'ajax-test/dialog-close',
+          'attributes' => array(
+            'class' => array('use-ajax'),
+          ),
+        ),
+        'link5' => array(
+          'title' => 'Link 5 (form)',
+          'href' => 'ajax-test/dialog-form',
+          'attributes' => array(
+            'class' => array('use-ajax'),
+            'data-accepts' => 'application/vnd.drupal-modal',
+          ),
+        ),
+        'link6' => array(
+          'title' => 'Link 6 (entity form)',
+          'href' => 'admin/structure/contact/add',
+          'attributes' => array(
+            'class' => array('use-ajax'),
+            'data-accepts' => 'application/vnd.drupal-modal',
+            'data-dialog-options' => json_encode(array(
+              'width' => 800,
+              'height' => 500,
+            ))
+          ),
+        ),
+        'link7' => array(
+          'title' => 'Link 7 (non-modal, no target)',
+          'href' => 'ajax-test/dialog-contents',
+          'attributes' => array(
+            'class' => array('use-ajax'),
+            'data-accepts' => 'application/vnd.drupal-dialog',
+            'data-dialog-options' => json_encode(array(
+              'width' => 800,
+            ))
+          ),
+        ),
+      ),
+    );
+    return $build;
   }
 
   /**
-   * @todo Remove ajax_test_dialog_close().
+   * Close the ajax dialog.
    */
   public function dialogClose() {
-    return ajax_test_dialog_close();
+    $response = new AjaxResponse();
+    $response->addCommand(new CloseDialogCommand('#ajax-test-dialog-wrapper-1'));
+    return $response;
   }
 
 }