diff --git a/core/modules/editor/lib/Drupal/editor/Form/EditorImageDialog.php b/core/modules/editor/lib/Drupal/editor/Form/EditorImageDialog.php
index 0807210..353b94b 100644
--- a/core/modules/editor/lib/Drupal/editor/Form/EditorImageDialog.php
+++ b/core/modules/editor/lib/Drupal/editor/Form/EditorImageDialog.php
@@ -7,19 +7,18 @@
 
 namespace Drupal\editor\Form;
 
-use Drupal\Core\Form\FormInterface;
+use Drupal\Core\Form\FormBase;
 use Drupal\filter\Entity\FilterFormat;
 use Drupal\Core\Ajax\AjaxResponse;
 use Drupal\Core\Ajax\HtmlCommand;
 use Drupal\editor\Ajax\EditorDialogSave;
 use Drupal\Core\Ajax\CloseModalDialogCommand;
-use Drupal\Core\StreamWrapper\LocalStream;
-use Drupal\file\FileInterface;
+
 
 /**
  * Provides an image dialog for text editors.
  */
-class EditorImageDialog implements FormInterface {
+class EditorImageDialog extends FormBase {
 
   /**
    * {@inheritdoc}
@@ -59,7 +58,7 @@ public function buildForm(array $form, array &$form_state, FilterFormat $filter_
     $fid = $existing_file ? $existing_file->id() : NULL;
 
     $form['fid'] = array(
-      '#title' => t('Image'),
+      '#title' => $this->t('Image'),
       '#type' => 'managed_file',
       '#upload_location' => $editor->image_upload['scheme'] . '://' .$editor->image_upload['directory'],
       '#default_value' => $fid ? array($fid) : NULL,
@@ -72,7 +71,7 @@ public function buildForm(array $form, array &$form_state, FilterFormat $filter_
     );
 
     $form['attributes']['src'] = array(
-     '#title' => t('URL'),
+     '#title' => $this->t('URL'),
      '#type' => 'textfield',
      '#default_value' => isset($input['src']) ? $input['src'] : '',
      '#maxlength' => 2048,
@@ -89,19 +88,19 @@ public function buildForm(array $form, array &$form_state, FilterFormat $filter_
     }
 
     $form['attributes']['alt'] = array(
-      '#title' => t('Alternative text'),
+      '#title' => $this->t('Alternative text'),
       '#type' => 'textfield',
       '#default_value' => isset($input['alt']) ? $input['alt'] : '',
       '#maxlength' => 2048,
     );
     $form['dimensions'] = array(
       '#type' => 'item',
-      '#title' => t('Image size'),
+      '#title' => $this->t('Image size'),
       '#field_prefix' => '<div class="container-inline">',
       '#field_suffix' => '</div>',
     );
     $form['dimensions']['width'] = array(
-      '#title' => t('Width'),
+      '#title' => $this->t('Width'),
       '#title_display' => 'invisible',
       '#type' => 'number',
       '#default_value' => isset($input['width']) ? $input['width'] : '',
@@ -114,7 +113,7 @@ public function buildForm(array $form, array &$form_state, FilterFormat $filter_
       '#parents' => array('attributes', 'width'),
     );
     $form['dimensions']['height'] = array(
-      '#title' => t('Height'),
+      '#title' => $this->t('Height'),
       '#title_display' => 'invisible',
       '#type' => 'number',
       '#default_value' => isset($input['height']) ? $input['height'] : '',
@@ -132,7 +131,7 @@ public function buildForm(array $form, array &$form_state, FilterFormat $filter_
     );
     $form['actions']['save_modal'] = array(
       '#type' => 'submit',
-      '#value' => t('Save'),
+      '#value' => $this->t('Save'),
       // No regular submit-handler. This form only works via JavaScript.
       '#submit' => array(),
       '#ajax' => array(
@@ -147,12 +146,6 @@ public function buildForm(array $form, array &$form_state, FilterFormat $filter_
   /**
    * {@inheritdoc}
    */
-  public function validateForm(array &$form, array &$form_state) {
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function submitForm(array &$form, array &$form_state) {
     $response = new AjaxResponse();
 
diff --git a/core/modules/editor/lib/Drupal/editor/Form/EditorLinkDialog.php b/core/modules/editor/lib/Drupal/editor/Form/EditorLinkDialog.php
index e796687..c2c17e1 100644
--- a/core/modules/editor/lib/Drupal/editor/Form/EditorLinkDialog.php
+++ b/core/modules/editor/lib/Drupal/editor/Form/EditorLinkDialog.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\editor\Form;
 
-use Drupal\Core\Form\FormInterface;
+use Drupal\Core\Form\FormBase;
 use Drupal\filter\Entity\FilterFormat;
 use Drupal\Core\Ajax\AjaxResponse;
 use Drupal\Core\Ajax\HtmlCommand;
@@ -17,7 +17,7 @@
 /**
  * Provides a link dialog for text editors.
  */
-class EditorLinkDialog implements FormInterface {
+class EditorLinkDialog extends FormBase {
 
   /**
    * {@inheritdoc}
@@ -45,14 +45,14 @@ public function buildForm(array $form, array &$form_state, FilterFormat $filter_
     // Everything under the "attributes" key is merged directly into the
     // generated link tag's attributes.
     $form['attributes']['href'] = array(
-      '#title' => t('URL'),
+      '#title' => $this->t('URL'),
       '#type' => 'textfield',
       '#default_value' => isset($input['href']) ? $input['href'] : '',
       '#maxlength' => 2048,
     );
 
     $form['attributes']['target'] = array(
-      '#title' => t('Open in new window'),
+      '#title' => $this->t('Open in new window'),
       '#type' => 'checkbox',
       '#default_value' => !empty($input['target']),
       '#return_value' => '_blank',
@@ -63,7 +63,7 @@ public function buildForm(array $form, array &$form_state, FilterFormat $filter_
     );
     $form['actions']['save_modal'] = array(
       '#type' => 'submit',
-      '#value' => t('Save'),
+      '#value' => $this->t('Save'),
       // No regular submit-handler. This form only works via JavaScript.
       '#submit' => array(),
       '#ajax' => array(
@@ -78,12 +78,6 @@ public function buildForm(array $form, array &$form_state, FilterFormat $filter_
   /**
    * {@inheritdoc}
    */
-  public function validateForm(array &$form, array &$form_state) {
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function submitForm(array &$form, array &$form_state) {
     $response = new AjaxResponse();