diff --git a/core/includes/form.inc b/core/includes/form.inc
index d8349d0..d44f527 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -54,18 +54,6 @@ function drupal_form_submit($form_arg, FormStateInterface $form_state) {
 }
 
 /**
- * Processes a form submission.
- *
- * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
- *   Use \Drupal::formBuilder()->processForm().
- *
- * @see \Drupal\Core\Form\FormBuilderInterface::processForm().
- */
-function drupal_process_form($form_id, &$form, FormStateInterface $form_state) {
-  \Drupal::formBuilder()->processForm($form_id, $form, $form_state);
-}
-
-/**
  * Executes custom validation and submission handlers for a given form.
  *
  * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
diff --git a/core/modules/field/src/Tests/FieldAttachOtherTest.php b/core/modules/field/src/Tests/FieldAttachOtherTest.php
index d41808f..7d764d8 100644
--- a/core/modules/field/src/Tests/FieldAttachOtherTest.php
+++ b/core/modules/field/src/Tests/FieldAttachOtherTest.php
@@ -333,7 +333,7 @@ function testEntityFormDisplayExtractFormValues() {
     // Pretend the form has been built.
     $form_state['build_info']['callback_object'] = \Drupal::entityManager()->getFormObject($entity_type, 'default');
     \Drupal::formBuilder()->prepareForm('field_test_entity_form', $form, $form_state);
-    drupal_process_form('field_test_entity_form', $form, $form_state);
+    \Drupal::formBuilder()->processForm('field_test_entity_form', $form, $form_state);
     $form_state->setValue($this->fieldTestData->field_name, $values);
     $form_state->setValue($this->fieldTestData->field_name_2, $values_2);
 
diff --git a/core/modules/file/src/Controller/FileWidgetAjaxController.php b/core/modules/file/src/Controller/FileWidgetAjaxController.php
index 1198672..7544572 100644
--- a/core/modules/file/src/Controller/FileWidgetAjaxController.php
+++ b/core/modules/file/src/Controller/FileWidgetAjaxController.php
@@ -58,7 +58,7 @@ public function upload(Request $request) {
     $current_file_count = isset($current_element['#file_upload_delta']) ? $current_element['#file_upload_delta'] : 0;
 
     // Process user input. $form and $form_state are modified in the process.
-    drupal_process_form($form['#form_id'], $form, $form_state);
+    \Drupal::formBuilder()->processForm($form['#form_id'], $form, $form_state);
 
     // Retrieve the element to be rendered.
     $form = NestedArray::getValue($form, $form_parents);
diff --git a/core/modules/system/src/Controller/FormAjaxController.php b/core/modules/system/src/Controller/FormAjaxController.php
index 5285cfd..2b5784d 100644
--- a/core/modules/system/src/Controller/FormAjaxController.php
+++ b/core/modules/system/src/Controller/FormAjaxController.php
@@ -64,7 +64,7 @@ public static function create(ContainerInterface $container) {
    */
   public function content(Request $request) {
     list($form, $form_state) = $this->getForm($request);
-    drupal_process_form($form['#form_id'], $form, $form_state);
+    \Drupal::formBuilder()->processForm($form['#form_id'], $form, $form_state);
 
     // We need to return the part of the form (or some other content) that needs
     // to be re-rendered so the browser can update the page with changed content.
diff --git a/core/modules/system/src/Tests/Form/ElementsTableSelectTest.php b/core/modules/system/src/Tests/Form/ElementsTableSelectTest.php
index 0bde8d0..0beaf07 100644
--- a/core/modules/system/src/Tests/Form/ElementsTableSelectTest.php
+++ b/core/modules/system/src/Tests/Form/ElementsTableSelectTest.php
@@ -222,7 +222,7 @@ private function formSubmitHelper($form, $edit) {
 
     \Drupal::formBuilder()->prepareForm($form_id, $form, $form_state);
 
-    drupal_process_form($form_id, $form, $form_state);
+    \Drupal::formBuilder()->processForm($form_id, $form, $form_state);
 
     $errors = $form_state->getErrors();
 
diff --git a/core/modules/system/src/Tests/Form/FormTest.php b/core/modules/system/src/Tests/Form/FormTest.php
index be8d7e0..45c798f 100644
--- a/core/modules/system/src/Tests/Form/FormTest.php
+++ b/core/modules/system/src/Tests/Form/FormTest.php
@@ -117,7 +117,7 @@ function testRequiredFields() {
           // so we bypass it by setting the token to FALSE.
           $form['#token'] = FALSE;
           \Drupal::formBuilder()->prepareForm($form_id, $form, $form_state);
-          drupal_process_form($form_id, $form, $form_state);
+          \Drupal::formBuilder()->processForm($form_id, $form, $form_state);
           $errors = $form_state->getErrors();
           // Form elements of type 'radios' throw all sorts of PHP notices
           // when you try to render them like this, so we ignore those for