3414294-submitting-form-throws: Fixed the messenger issue.

src/Form/NodeTitleValidationAdminForm.php

@@ -7,6 +7,7 @@ use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Entity\EntityTypeManager;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Messenger\MessengerInterface;
 
 /**
  * Class NodeTitleValidationAdminForm.
@@ -29,6 +30,13 @@ class NodeTitleValidationAdminForm extends FormBase {
    */
   protected $configFactory;
 
+  /**
+   * The messenger service.
+   *
+   * @var \Drupal\Core\Messenger\MessengerInterface
+   */
+  protected $messenger;
+  
   /**
    * Constructs a new NodeTitleValidationController.
    *
@@ -37,9 +45,10 @@ class NodeTitleValidationAdminForm extends FormBase {
    * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The configFactory.
    */
-  public function __construct(EntityTypeManager $entityTypeManager, ConfigFactoryInterface $config_factory) {
+  public function __construct(EntityTypeManager $entityTypeManager, ConfigFactoryInterface $config_factory, MessengerInterface $messenger) {
     $this->entityTypeManager = $entityTypeManager;
     $this->configFactory = $config_factory;
+    $this->messenger = $messenger;
   }
 
   /**
@@ -48,7 +57,8 @@ class NodeTitleValidationAdminForm extends FormBase {
   public static function create(ContainerInterface $container) {
     return new static(
       $container->get('entity_type.manager'),
-      $container->get('config.factory')
+      $container->get('config.factory'),
+      $container->get('messenger')
     );
   }