diff --git a/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/Form/FormTestForm.php b/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/Form/FormTestForm.php
index 7b13932..005738c 100644
--- a/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/Form/FormTestForm.php
+++ b/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/Form/FormTestForm.php
@@ -67,60 +67,6 @@ public function validatePattern() {
   }
 
   /**
-   * Wraps _form_test_tableselect_multiple_true_form().
-   *
-   * @todo Remove _form_test_tableselect_multiple_true_form().
-   */
-  public function testTableSelectCheckboxes() {
-    return drupal_get_form('_form_test_tableselect_multiple_true_form');
-  }
-
-  /**
-   * Wraps _form_test_tableselect_multiple_false_form().
-   *
-   * @todo Remove _form_test_tableselect_multiple_false_form().
-   */
-  public function testTableSelectRadios() {
-    return drupal_get_form('_form_test_tableselect_multiple_false_form');
-  }
-
-  /**
-   * Wraps _form_test_tableselect_colspan_form().
-   *
-   * @todo Remove _form_test_tableselect_colspan_form().
-   */
-  public function testTableSelectColspan() {
-    return drupal_get_form('_form_test_tableselect_colspan_form');
-  }
-
-  /**
-   * Wraps _form_test_tableselect_empty_form().
-   *
-   * @todo Remove _form_test_tableselect_empty_form().
-   */
-  public function testTableSelectEmptyText() {
-    return drupal_get_form('_form_test_tableselect_empty_form');
-  }
-
-  /**
-   * Wraps _form_test_tableselect_js_select_form().
-   *
-   * @todo Remove _form_test_tableselect_js_select_form().
-   */
-  public function testTableSelectJS($test_action) {
-    return drupal_get_form('_form_test_tableselect_js_select_form', $test_action);
-  }
-
-  /**
-   * Wraps _form_test_vertical_tabs_form().
-   *
-   * @todo Remove _form_test_vertical_tabs_form().
-   */
-  public function testVerticalTabs() {
-    return drupal_get_form('_form_test_vertical_tabs_form');
-  }
-
-  /**
    * Wraps form_test_storage_form().
    *
    * @todo Remove form_test_storage_form().
@@ -148,15 +94,6 @@ public function testFormStateCleanAdvanced() {
   }
 
   /**
-   * Wraps _form_test_checkbox().
-   *
-   * @todo Remove _form_test_checkbox().
-   */
-  public function testCheckbox() {
-    return drupal_get_form('_form_test_checkbox');
-  }
-
-  /**
    * Wraps form_test_select().
    *
    * @todo Remove form_test_select().
@@ -273,16 +210,6 @@ public function testDisabledElements() {
     return drupal_get_form('_form_test_disabled_elements');
   }
 
-  /**
-   * Wraps _form_test_input_forgery().
-   *
-   * @todo Remove _form_test_input_forgery().
-   */
-  public function testInputForgery() {
-    return drupal_get_form('_form_test_input_forgery');
-  }
-
-  /**
    * Wraps form_test_form_rebuild_preserve_values_form().
    *
    * @todo Remove form_test_form_rebuild_preserve_values_form().
diff --git a/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestCheckboxForm.php b/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestCheckboxForm.php
index 1caa231..43acba9 100644
--- a/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestCheckboxForm.php
+++ b/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestCheckboxForm.php
@@ -8,6 +8,7 @@
 namespace Drupal\form_test;
 
 use Drupal\Core\Form\FormBase;
+use Symfony\Component\HttpFoundation\JsonResponse;
 
 class FormTestCheckboxForm extends FormBase {
   /**
@@ -21,8 +22,6 @@ public function getFormId() {
    * {@inheritdoc}
    */
   public function buildForm(array $form, array &$form_state) {
-    $form['#submit'] = array('_form_test_submit_values_json');
-
     // A required checkbox.
     $form['required_checkbox'] = array(
       '#type' => 'checkbox',
@@ -91,5 +90,9 @@ public function buildForm(array $form, array &$form_state) {
    * {@inheritdoc}
    */
   public function submitForm(array &$form, array &$form_state) {
+    $response = new JsonResponse($form_state['values']);
+    // @todo remove once converted to new routing system.
+    $response->send();
+    exit;
   }
 }
diff --git a/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestInputForgeryForm.php b/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestInputForgeryForm.php
index 43ab396..601128e 100644
--- a/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestInputForgeryForm.php
+++ b/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestInputForgeryForm.php
@@ -8,6 +8,7 @@
 namespace Drupal\form_test;
 
 use Drupal\Core\Form\FormBase;
+use Symfony\Component\HttpFoundation\JsonResponse;
 
 class FormTestInputForgeryForm extends FormBase {
   /**
@@ -21,8 +22,6 @@ public function getFormId() {
    * {@inheritdoc}
    */
   public function buildForm(array $form, array &$form_state) {
-    $form['#submit'] = array('_form_test_submit_values_json');
-
     // For testing that a user can't submit a value not matching one of the
     // allowed options.
     $form['checkboxes'] = array(
@@ -45,5 +44,6 @@ public function buildForm(array $form, array &$form_state) {
    * {@inheritdoc}
    */
   public function submitForm(array &$form, array &$form_state) {
+    return new JsonResponse($form_state['values']);
   }
 }
diff --git a/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestTableSelectJsSelectForm.php b/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestTableSelectJsSelectForm.php
index cc0292f..ce907d0 100644
--- a/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestTableSelectJsSelectForm.php
+++ b/core/modules/system/tests/modules/form_test/lib/Drupal/form_test/FormTestTableSelectJsSelectForm.php
@@ -22,7 +22,7 @@ public function getFormId() {
    * {@inheritdoc}
    */
   public function buildForm(array $form, array &$form_state, $test_action = NULL) {
-    switch (String::checkPlain($test_action)) {
+    switch ($test_action) {
       case 'multiple-true-default':
         $options = array('#multiple' => TRUE);
         break;
@@ -40,7 +40,7 @@ public function buildForm(array $form, array &$form_state, $test_action = NULL)
         break;
     }
 
-    return _form_test_tableselect_form_builder($form, $form_state, $options);;
+    return _form_test_tableselect_form_builder($form, $form_state, $options);
   }
 
   /**