File::preDelete

public static File::preDelete(EntityStorageInterface $storage, array $entities)

public static function preDelete(EntityStorageInterface $storage, array $entities) {
  parent::preDelete($storage, $entities);

  foreach ($entities as $entity) {
    // Delete all remaining references to this file.
    $file_usage = \Drupal::service('file.usage')->listUsage($entity);
    if (!empty($file_usage)) {
      foreach ($file_usage as $module => $usage) {
        \Drupal::service('file.usage')->delete($entity, $module);
      }
    }
    // Delete the actual file. Failures due to invalid files and files that
    // were already deleted are logged to watchdog but ignored, the
    // corresponding file entity will be deleted.
    file_unmanaged_delete($entity->getFileUri());
  }
}