diff --git a/core/includes/form.inc b/core/includes/form.inc
index 70870ce..78a4f7a 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -11,6 +11,7 @@
 use Drupal\Component\Utility\UrlHelper;
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Database\Database;
+use Drupal\Core\Form\FormOptionsHelper;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Form\OptGroup;
 use Drupal\Core\Render\Element;
@@ -19,11 +20,6 @@
 use Symfony\Component\HttpFoundation\RedirectResponse;
 
 /**
- * Identifies a 'None' option key.
- */
-const OPTIONS_EMPTY_OPTION = '_none';
-
-/**
  * Retrieves, populates, and processes a form.
  *
  * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
@@ -62,78 +58,11 @@ function template_preprocess_select(&$variables) {
 /**
  * Converts an array of options into HTML, for use in select list form elements.
  *
- * This function calls itself recursively to obtain the values for each optgroup
- * within the list of options and when the function encounters an object with
- * an 'options' property inside $element['#options'].
- *
- * @param array $element
- *   An associative array containing the following key-value pairs:
- *   - #multiple: Optional Boolean indicating if the user may select more than
- *     one item.
- *   - #options: An associative array of options to render as HTML. Each array
- *     value can be a string, an array, or an object with an 'option' property:
- *     - A string or integer key whose value is a translated string is
- *       interpreted as a single HTML option element. Do not use placeholders
- *       that sanitize data: doing so will lead to double-escaping. Note that
- *       the key will be visible in the HTML and could be modified by malicious
- *       users, so don't put sensitive information in it.
- *     - A translated string key whose value is an array indicates a group of
- *       options. The translated string is used as the label attribute for the
- *       optgroup. Do not use placeholders to sanitize data: doing so will lead
- *       to double-escaping. The array should contain the options you wish to
- *       group and should follow the syntax of $element['#options'].
- *     - If the function encounters a string or integer key whose value is an
- *       object with an 'option' property, the key is ignored, the contents of
- *       the option property are interpreted as $element['#options'], and the
- *       resulting HTML is added to the output.
- *   - #value: Optional integer, string, or array representing which option(s)
- *     to pre-select when the list is first displayed. The integer or string
- *     must match the key of an option in the '#options' list. If '#multiple' is
- *     TRUE, this can be an array of integers or strings.
- * @param array|null $choices
- *   (optional) Either an associative array of options in the same format as
- *   $element['#options'] above, or NULL. This parameter is only used internally
- *   and is not intended to be passed in to the initial function call.
- *
- * @return string
- *   An HTML string of options and optgroups for use in a select form element.
+ * @deprecated in Drupal 8.0.x-dev, will be removed before Drupal 8.0.0.
+ *   Use \Drupal\Core\Form\FormOptionsHelper::formSelectOptions().
  */
 function form_select_options($element, $choices = NULL) {
-  if (!isset($choices)) {
-    if (empty($element['#options'])) {
-      return '';
-    }
-    $choices = $element['#options'];
-  }
-  // array_key_exists() accommodates the rare event where $element['#value'] is NULL.
-  // isset() fails in this situation.
-  $value_valid = isset($element['#value']) || array_key_exists('#value', $element);
-  $value_is_array = $value_valid && is_array($element['#value']);
-  // Check if the element is multiple select and no value has been selected.
-  $empty_value = (empty($element['#value']) && !empty($element['#multiple']));
-  $options = '';
-  foreach ($choices as $key => $choice) {
-    if (is_array($choice)) {
-      $options .= '<optgroup label="' . String::checkPlain($key) . '">';
-      $options .= form_select_options($element, $choice);
-      $options .= '</optgroup>';
-    }
-    elseif (is_object($choice) && isset($choice->option)) {
-      $options .= form_select_options($element, $choice->option);
-    }
-    else {
-      $key = (string) $key;
-      $empty_choice = $empty_value && $key == OPTIONS_EMPTY_OPTION;
-      if ($value_valid && ((!$value_is_array && (string) $element['#value'] === $key || ($value_is_array && in_array($key, $element['#value']))) || $empty_choice)) {
-        $selected = ' selected="selected"';
-      }
-      else {
-        $selected = '';
-      }
-      $options .= '<option value="' . String::checkPlain($key) . '"' . $selected . '>' . String::checkPlain($choice) . '</option>';
-    }
-  }
-  return SafeMarkup::set($options);
+  return FormOptionsHelper::formSelectOptions($element, $choices);
 }
 
 /**
diff --git a/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php b/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php
index 267e0f4..87b8257 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php
@@ -12,6 +12,7 @@
 use Drupal\Core\Database\Query\SelectInterface;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Form\FormOptionsHelper;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Entity\EntityReferenceSelection\SelectionInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
@@ -113,7 +114,7 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
     $selection_handler_settings += array(
       'target_bundles' => array(),
       'sort' => array(
-        'field' => OPTIONS_EMPTY_OPTION,
+        'field' => FormOptionsHelper::OPTIONS_EMPTY_OPTION,
       ),
       'auto_create' => FALSE,
     );
@@ -169,7 +170,7 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
         '#type' => 'select',
         '#title' => $this->t('Sort by'),
         '#options' => array(
-          OPTIONS_EMPTY_OPTION => $this->t('- None -'),
+          FormOptionsHelper::OPTIONS_EMPTY_OPTION => $this->t('- None -'),
         ) + $fields,
         '#ajax' => TRUE,
         '#limit_validation_errors' => array(),
@@ -182,7 +183,7 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
         '#process' => array('_entity_reference_form_process_merge_parent'),
       );
 
-      if ($selection_handler_settings['sort']['field'] != OPTIONS_EMPTY_OPTION) {
+      if ($selection_handler_settings['sort']['field'] != FormOptionsHelper::OPTIONS_EMPTY_OPTION) {
         // Merge-in default values.
         $selection_handler_settings['sort'] += array(
           'direction' => 'ASC',
@@ -345,7 +346,7 @@ protected function buildEntityQuery($match = NULL, $match_operator = 'CONTAINS')
     // Add the sort option.
     if (!empty($handler_settings['sort'])) {
       $sort_settings = $handler_settings['sort'];
-      if ($sort_settings['field'] != OPTIONS_EMPTY_OPTION) {
+      if ($sort_settings['field'] != FormOptionsHelper::OPTIONS_EMPTY_OPTION) {
         $query->sort($sort_settings['field'], $sort_settings['direction']);
       }
     }
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php
index 83cb9cc..06d4483 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php
@@ -11,6 +11,7 @@
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Field\WidgetBase;
+use Drupal\Core\Form\FormOptionsHelper;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Form\OptGroup;
 
@@ -81,7 +82,7 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
    *   The form state.
    */
   public static function validateElement(array $element, FormStateInterface $form_state) {
-    if ($element['#required'] && $element['#value'] == OPTIONS_EMPTY_OPTION) {
+    if ($element['#required'] && $element['#value'] == FormOptionsHelper::OPTIONS_EMPTY_OPTION) {
       $form_state->setError($element, t('!name field is required.', array('!name' => $element['#title'])));
     }
 
@@ -99,7 +100,7 @@ public static function validateElement(array $element, FormStateInterface $form_
 
     // Filter out the 'none' option. Use a strict comparison, because
     // 0 == 'any string'.
-    $index = array_search(OPTIONS_EMPTY_OPTION, $values, TRUE);
+    $index = array_search(FormOptionsHelper::OPTIONS_EMPTY_OPTION, $values, TRUE);
     if ($index !== FALSE) {
       unset($values[$index]);
     }
@@ -141,7 +142,7 @@ protected function getOptions(FieldableEntityInterface $entity) {
             break;
         }
 
-        $options = array(OPTIONS_EMPTY_OPTION => $label) + $options;
+        $options = array(FormOptionsHelper::OPTIONS_EMPTY_OPTION => $label) + $options;
       }
 
       $module_handler = \Drupal::moduleHandler();
diff --git a/core/lib/Drupal/Core/Form/FormOptionsHelper.php b/core/lib/Drupal/Core/Form/FormOptionsHelper.php
index 12e4d75..e3c2673 100644
--- a/core/lib/Drupal/Core/Form/FormOptionsHelper.php
+++ b/core/lib/Drupal/Core/Form/FormOptionsHelper.php
@@ -7,10 +7,93 @@
 
 namespace Drupal\Core\Form;
 
+use Drupal\Component\Utility\SafeMarkup;
+
 /**
  * @todo.
  */
 class FormOptionsHelper {
 
+  /**
+   * Identifies a 'None' option key.
+   */
+  const OPTIONS_EMPTY_OPTION = '_none';
+
+  /**
+   * Converts an array of options into HTML, for use in select list form elements.
+   *
+   * This function calls itself recursively to obtain the values for each optgroup
+   * within the list of options and when the function encounters an object with
+   * an 'options' property inside $element['#options'].
+   *
+   * @param array $element
+   *   An associative array containing the following key-value pairs:
+   *   - #multiple: Optional Boolean indicating if the user may select more than
+   *     one item.
+   *   - #options: An associative array of options to render as HTML. Each array
+   *     value can be a string, an array, or an object with an 'option' property:
+   *     - A string or integer key whose value is a translated string is
+   *       interpreted as a single HTML option element. Do not use placeholders
+   *       that sanitize data: doing so will lead to double-escaping. Note that
+   *       the key will be visible in the HTML and could be modified by malicious
+   *       users, so don't put sensitive information in it.
+   *     - A translated string key whose value is an array indicates a group of
+   *       options. The translated string is used as the label attribute for the
+   *       optgroup. Do not use placeholders to sanitize data: doing so will lead
+   *       to double-escaping. The array should contain the options you wish to
+   *       group and should follow the syntax of $element['#options'].
+   *     - If the function encounters a string or integer key whose value is an
+   *       object with an 'option' property, the key is ignored, the contents of
+   *       the option property are interpreted as $element['#options'], and the
+   *       resulting HTML is added to the output.
+   *   - #value: Optional integer, string, or array representing which option(s)
+   *     to pre-select when the list is first displayed. The integer or string
+   *     must match the key of an option in the '#options' list. If '#multiple' is
+   *     TRUE, this can be an array of integers or strings.
+   * @param array|null $choices
+   *   (optional) Either an associative array of options in the same format as
+   *   $element['#options'] above, or NULL. This parameter is only used internally
+   *   and is not intended to be passed in to the initial function call.
+   *
+   * @return string
+   *   An HTML string of options and optgroups for use in a select form element.
+   */
+  public static function formSelectOptions(array $element, $choices = NULL) {
+    if (!isset($choices)) {
+      if (empty($element['#options'])) {
+        return '';
+      }
+      $choices = $element['#options'];
+    }
+    // array_key_exists() accommodates the rare event where $element['#value'] is NULL.
+    // isset() fails in this situation.
+    $value_valid = isset($element['#value']) || array_key_exists('#value', $element);
+    $value_is_array = $value_valid && is_array($element['#value']);
+    // Check if the element is multiple select and no value has been selected.
+    $empty_value = (empty($element['#value']) && !empty($element['#multiple']));
+    $options = '';
+    foreach ($choices as $key => $choice) {
+      if (is_array($choice)) {
+        $options .= '<optgroup label="' . SafeMarkup::checkPlain($key) . '">';
+        $options .= static::formSelectOptions($element, $choice);
+        $options .= '</optgroup>';
+      }
+      elseif (is_object($choice) && isset($choice->option)) {
+        $options .= static::formSelectOptions($element, $choice->option);
+      }
+      else {
+        $key = (string) $key;
+        $empty_choice = $empty_value && $key == static::OPTIONS_EMPTY_OPTION;
+        if ($value_valid && ((!$value_is_array && (string) $element['#value'] === $key || ($value_is_array && in_array($key, $element['#value']))) || $empty_choice)) {
+          $selected = ' selected="selected"';
+        }
+        else {
+          $selected = '';
+        }
+        $options .= '<option value="' . SafeMarkup::checkPlain($key) . '"' . $selected . '>' . SafeMarkup::checkPlain($choice) . '</option>';
+      }
+    }
+    return SafeMarkup::set($options);
+  }
+
 }
- 
\ No newline at end of file
diff --git a/core/modules/entity_reference/src/Tests/EntityReferenceAdminTest.php b/core/modules/entity_reference/src/Tests/EntityReferenceAdminTest.php
index f61c801..d8efae5 100644
--- a/core/modules/entity_reference/src/Tests/EntityReferenceAdminTest.php
+++ b/core/modules/entity_reference/src/Tests/EntityReferenceAdminTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\entity_reference\Tests;
 
+use Drupal\Core\Form\FormOptionsHelper;
 use Drupal\field_ui\Tests\FieldUiTestTrait;
 use Drupal\simpletest\WebTestBase;
 use Drupal\taxonomy\Entity\Vocabulary;
@@ -97,7 +98,7 @@ public function testFieldAdminHandler() {
 
     // Test the sort settings.
     // Option 0: no sort.
-    $this->assertFieldByName('field[settings][handler_settings][sort][field]', OPTIONS_EMPTY_OPTION);
+    $this->assertFieldByName('field[settings][handler_settings][sort][field]', FormOptionsHelper::OPTIONS_EMPTY_OPTION);
     $this->assertNoFieldByName('field[settings][handler_settings][sort][direction]');
     // Option 1: sort by field.
     $this->drupalPostAjaxForm(NULL, array('field[settings][handler_settings][sort][field]' => 'nid'), 'field[settings][handler_settings][sort][field]');
@@ -111,7 +112,7 @@ public function testFieldAdminHandler() {
     $this->assertFieldByXPath("//select[@name='field[settings][handler_settings][sort][field]']/option[@value='body.value']");
 
     // Set back to no sort.
-    $this->drupalPostAjaxForm(NULL, array('field[settings][handler_settings][sort][field]' => OPTIONS_EMPTY_OPTION), 'field[settings][handler_settings][sort][field]');
+    $this->drupalPostAjaxForm(NULL, array('field[settings][handler_settings][sort][field]' => FormOptionsHelper::OPTIONS_EMPTY_OPTION), 'field[settings][handler_settings][sort][field]');
     $this->assertNoFieldByName('field[settings][handler_settings][sort][direction]');
 
     // Third step: confirm.
@@ -147,7 +148,7 @@ public function testFieldAdminHandler() {
     );
     $this->drupalPostForm($bundle_path . '/fields/' . $field_name . '/storage', $edit, t('Save field settings'));
     $this->drupalGet($bundle_path . '/fields/' . $field_name);
-    $this->assertFieldByName('field[settings][handler_settings][filter][type]', OPTIONS_EMPTY_OPTION);
+    $this->assertFieldByName('field[settings][handler_settings][filter][type]', FormOptionsHelper::OPTIONS_EMPTY_OPTION);
 
     // Try to select the views handler.
     $edit = array(
diff --git a/core/modules/entity_reference/src/Tests/EntityReferenceFieldDefaultValueTest.php b/core/modules/entity_reference/src/Tests/EntityReferenceFieldDefaultValueTest.php
index 642bfa0..4c6f0d6 100644
--- a/core/modules/entity_reference/src/Tests/EntityReferenceFieldDefaultValueTest.php
+++ b/core/modules/entity_reference/src/Tests/EntityReferenceFieldDefaultValueTest.php
@@ -9,6 +9,7 @@
 
 use Drupal\Component\Utility\Unicode;
 use Drupal\config\Tests\SchemaCheckTestTrait;
+use Drupal\Core\Form\FormOptionsHelper;
 use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\simpletest\WebTestBase;
 
@@ -68,7 +69,7 @@ function testEntityReferenceDefaultValue() {
         'handler' => 'default',
         'handler_settings' => array(
           'target_bundles' => array('referenced_content'),
-          'sort' => array('field' => OPTIONS_EMPTY_OPTION),
+          'sort' => array('field' => FormOptionsHelper::OPTIONS_EMPTY_OPTION),
         ),
       ),
     ));
@@ -131,7 +132,7 @@ function testEntityReferenceDefaultConfigValue() {
       'settings' => array(
         'handler' => 'default',
         'handler_settings' => array(
-          'sort' => array('field' => OPTIONS_EMPTY_OPTION),
+          'sort' => array('field' => FormOptionsHelper::OPTIONS_EMPTY_OPTION),
         ),
       ),
     ));
diff --git a/core/modules/options/options.api.php b/core/modules/options/options.api.php
index f54c4dd..c49ecd2 100644
--- a/core/modules/options/options.api.php
+++ b/core/modules/options/options.api.php
@@ -7,6 +7,7 @@
 
 use Drupal\Core\Entity\FieldableEntityInterface;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\Form\FormOptionsHelper;
 
 /**
  * Alters the list of options to be displayed for a field.
@@ -32,7 +33,7 @@ function hook_options_list_alter(array &$options, array $context) {
   // Check if this is the field we want to change.
   if ($context['field']->id() == 'field_option') {
     // Change the label of the empty option.
-    $options[OPTIONS_EMPTY_OPTION] = t('== Empty ==');
+    $options[FormOptionsHelper::OPTIONS_EMPTY_OPTION] = t('== Empty ==');
   }
 }
 
diff --git a/core/modules/options/src/Tests/OptionsSelectDynamicValuesTest.php b/core/modules/options/src/Tests/OptionsSelectDynamicValuesTest.php
index 844e81b..b27bfb4 100644
--- a/core/modules/options/src/Tests/OptionsSelectDynamicValuesTest.php
+++ b/core/modules/options/src/Tests/OptionsSelectDynamicValuesTest.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\options\Tests;
 
+use Drupal\Core\Form\FormOptionsHelper;
+
 /**
  * Tests an options select with a dynamic allowed values function.
  *
@@ -30,7 +32,7 @@ function testSelectListDynamic() {
     $this->assertEqual(count($options), count($this->test) + 1);
     foreach ($options as $option) {
       $value = (string) $option['value'];
-      if ($value != OPTIONS_EMPTY_OPTION) {
+      if ($value != FormOptionsHelper::OPTIONS_EMPTY_OPTION) {
         $this->assertTrue(array_search($value, $this->test));
       }
     }
diff --git a/core/modules/options/src/Tests/OptionsWidgetsTest.php b/core/modules/options/src/Tests/OptionsWidgetsTest.php
index a0a709a..f820614 100644
--- a/core/modules/options/src/Tests/OptionsWidgetsTest.php
+++ b/core/modules/options/src/Tests/OptionsWidgetsTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\options\Tests;
 
+use Drupal\Core\Form\FormOptionsHelper;
 use Drupal\field\Tests\FieldTestBase;
 
 /**
@@ -127,7 +128,7 @@ function testRadioButtons() {
     $this->assertNoFieldChecked('edit-card-1-2');
 
     // Unselect option.
-    $edit = array('card_1' => OPTIONS_EMPTY_OPTION);
+    $edit = array('card_1' => FormOptionsHelper::OPTIONS_EMPTY_OPTION);
     $this->drupalPostForm(NULL, $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_1', array());
 
@@ -257,17 +258,17 @@ function testSelectListSingle() {
     // Display form.
     $this->drupalGet('entity_test/manage/' . $entity->id());
     // A required field without any value has a "none" option.
-    $this->assertTrue($this->xpath('//select[@id=:id]//option[@value=:value and text()=:label]', array(':id' => 'edit-card-1', ':value' => OPTIONS_EMPTY_OPTION, ':label' => t('- Select a value -'))), 'A required select list has a "Select a value" choice.');
+    $this->assertTrue($this->xpath('//select[@id=:id]//option[@value=:value and text()=:label]', array(':id' => 'edit-card-1', ':value' => FormOptionsHelper::OPTIONS_EMPTY_OPTION, ':label' => t('- Select a value -'))), 'A required select list has a "Select a value" choice.');
 
     // With no field data, nothing is selected.
-    $this->assertNoOptionSelected('edit-card-1', OPTIONS_EMPTY_OPTION);
+    $this->assertNoOptionSelected('edit-card-1', FormOptionsHelper::OPTIONS_EMPTY_OPTION);
     $this->assertNoOptionSelected('edit-card-1', 0);
     $this->assertNoOptionSelected('edit-card-1', 1);
     $this->assertNoOptionSelected('edit-card-1', 2);
     $this->assertRaw('Some dangerous &amp; unescaped markup', 'Option text was properly filtered.');
 
     // Submit form: select invalid 'none' option.
-    $edit = array('card_1' => OPTIONS_EMPTY_OPTION);
+    $edit = array('card_1' => FormOptionsHelper::OPTIONS_EMPTY_OPTION);
     $this->drupalPostForm(NULL, $edit, t('Save'));
     $this->assertRaw(t('!title field is required.', array('!title' => $field->getName())), 'Cannot save a required field when selecting "none" from the select list.');
 
@@ -279,7 +280,7 @@ function testSelectListSingle() {
     // Display form: check that the right options are selected.
     $this->drupalGet('entity_test/manage/' . $entity->id());
     // A required field with a value has no 'none' option.
-    $this->assertFalse($this->xpath('//select[@id=:id]//option[@value=:value]', array(':id' => 'edit-card-1', ':value' => OPTIONS_EMPTY_OPTION)), 'A required select list with an actual value has no "none" choice.');
+    $this->assertFalse($this->xpath('//select[@id=:id]//option[@value=:value]', array(':id' => 'edit-card-1', ':value' => FormOptionsHelper::OPTIONS_EMPTY_OPTION)), 'A required select list with an actual value has no "none" choice.');
     $this->assertOptionSelected('edit-card-1', 0);
     $this->assertNoOptionSelected('edit-card-1', 1);
     $this->assertNoOptionSelected('edit-card-1', 2);
@@ -291,9 +292,9 @@ function testSelectListSingle() {
     // Display form.
     $this->drupalGet('entity_test/manage/' . $entity->id());
     // A non-required field has a 'none' option.
-    $this->assertTrue($this->xpath('//select[@id=:id]//option[@value=:value and text()=:label]', array(':id' => 'edit-card-1', ':value' => OPTIONS_EMPTY_OPTION, ':label' => t('- None -'))), 'A non-required select list has a "None" choice.');
+    $this->assertTrue($this->xpath('//select[@id=:id]//option[@value=:value and text()=:label]', array(':id' => 'edit-card-1', ':value' => FormOptionsHelper::OPTIONS_EMPTY_OPTION, ':label' => t('- None -'))), 'A non-required select list has a "None" choice.');
     // Submit form: Unselect the option.
-    $edit = array('card_1' => OPTIONS_EMPTY_OPTION);
+    $edit = array('card_1' => FormOptionsHelper::OPTIONS_EMPTY_OPTION);
     $this->drupalPostForm('entity_test/manage/' . $entity->id(), $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_1', array());
 
@@ -324,7 +325,7 @@ function testSelectListSingle() {
     $this->assertNoOptionSelected('edit-card-1', 2);
 
     // Submit form: Unselect the option.
-    $edit = array('card_1' => OPTIONS_EMPTY_OPTION);
+    $edit = array('card_1' => FormOptionsHelper::OPTIONS_EMPTY_OPTION);
     $this->drupalPostForm('entity_test/manage/' . $entity->id(), $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_1', array());
   }
@@ -355,7 +356,7 @@ function testSelectListMultiple() {
 
     // Display form: with no field data, nothing is selected.
     $this->drupalGet('entity_test/manage/' . $entity->id());
-    $this->assertOptionSelected("edit-card-2", OPTIONS_EMPTY_OPTION);
+    $this->assertOptionSelected("edit-card-2", FormOptionsHelper::OPTIONS_EMPTY_OPTION);
     $this->assertNoOptionSelected('edit-card-2', 0);
     $this->assertNoOptionSelected('edit-card-2', 1);
     $this->assertNoOptionSelected('edit-card-2', 2);
@@ -397,12 +398,12 @@ function testSelectListMultiple() {
 
     // Check that the 'none' option has no effect if actual options are selected
     // as well.
-    $edit = array('card_2[]' => array(OPTIONS_EMPTY_OPTION => OPTIONS_EMPTY_OPTION, 0 => 0));
+    $edit = array('card_2[]' => array(FormOptionsHelper::OPTIONS_EMPTY_OPTION => FormOptionsHelper::OPTIONS_EMPTY_OPTION, 0 => 0));
     $this->drupalPostForm('entity_test/manage/' . $entity->id(), $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_2', array(0));
 
     // Check that selecting the 'none' option empties the field.
-    $edit = array('card_2[]' => array(OPTIONS_EMPTY_OPTION => OPTIONS_EMPTY_OPTION));
+    $edit = array('card_2[]' => array(FormOptionsHelper::OPTIONS_EMPTY_OPTION => FormOptionsHelper::OPTIONS_EMPTY_OPTION));
     $this->drupalPostForm('entity_test/manage/' . $entity->id(), $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_2', array());
 
@@ -445,7 +446,7 @@ function testSelectListMultiple() {
     $this->assertNoOptionSelected('edit-card-2', 2);
 
     // Submit form: Unselect the option.
-    $edit = array('card_2[]' => array(OPTIONS_EMPTY_OPTION => OPTIONS_EMPTY_OPTION));
+    $edit = array('card_2[]' => array(FormOptionsHelper::OPTIONS_EMPTY_OPTION => FormOptionsHelper::OPTIONS_EMPTY_OPTION));
     $this->drupalPostForm('entity_test/manage/' . $entity->id(), $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_2', array());
   }
diff --git a/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php b/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
index a63079e..78b8577 100644
--- a/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
+++ b/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
@@ -10,6 +10,7 @@
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\Form\FormOptionsHelper;
 use Drupal\Core\Url;
 use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\field\Entity\FieldConfig;
@@ -244,7 +245,7 @@ protected function createReferenceTestEntities($referenced_entity) {
           'target_bundles' => array(
             $referenced_entity->bundle() => $referenced_entity->bundle(),
           ),
-          'sort' => array('field' => OPTIONS_EMPTY_OPTION),
+          'sort' => array('field' => FormOptionsHelper::OPTIONS_EMPTY_OPTION),
           'auto_create' => FALSE,
         ),
       ),
diff --git a/core/modules/user/src/Plugin/EntityReferenceSelection/UserSelection.php b/core/modules/user/src/Plugin/EntityReferenceSelection/UserSelection.php
index 9675da6..192ac9c 100644
--- a/core/modules/user/src/Plugin/EntityReferenceSelection/UserSelection.php
+++ b/core/modules/user/src/Plugin/EntityReferenceSelection/UserSelection.php
@@ -12,6 +12,7 @@
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Entity\Plugin\EntityReferenceSelection\SelectionBase;
 use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Form\FormOptionsHelper;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\user\RoleInterface;
@@ -85,7 +86,7 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
     // Merge in default values.
     $selection_handler_settings += array(
       'filter' => array(
-        'type' => OPTIONS_EMPTY_OPTION,
+        'type' => FormOptionsHelper::OPTIONS_EMPTY_OPTION,
       ),
       'include_anonymous' => TRUE,
     );
@@ -101,7 +102,7 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
       '#type' => 'select',
       '#title' => $this->t('Filter by'),
       '#options' => array(
-        OPTIONS_EMPTY_OPTION => $this->t('- None -'),
+        FormOptionsHelper::OPTIONS_EMPTY_OPTION => $this->t('- None -'),
         'role' => $this->t('User role'),
       ),
       '#ajax' => TRUE,