diff -u b/core/modules/media/media.services.yml b/core/modules/media/media.services.yml
--- b/core/modules/media/media.services.yml
+++ b/core/modules/media/media.services.yml
@@ -5,4 +4,0 @@
-
-  media.thumbnail_handler:
-    class: Drupal\media\MediaThumbnailHandler
-    arguments: ['@entity_type.manager', '@string_translation', '@config.factory']
diff -u b/core/modules/media/src/Entity/Media.php b/core/modules/media/src/Entity/Media.php
--- b/core/modules/media/src/Entity/Media.php
+++ b/core/modules/media/src/Entity/Media.php
@@ -7,6 +7,7 @@
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Field\BaseFieldDefinition;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\media\MediaInterface;
 use Drupal\Core\Entity\EntityChangedTrait;
 use Drupal\user\UserInterface;
@@ -78,6 +79,7 @@
 
   use EntityChangedTrait;
   use EntityPublishedTrait;
+  use StringTranslationTrait;
 
   /**
    * {@inheritdoc}
@@ -132,6 +134,65 @@
   }
 
   /**
+   * {@inheritdoc}
+   */
+  public function updateThumbnail($from_queue = FALSE) {
+    $file_storage = \Drupal::service('entity_type.manager')->getStorage('file');
+    $thumbnail_uri = $this->getThumbnailUri($from_queue);
+    $existing = $file_storage->getQuery()
+      ->condition('uri', $thumbnail_uri)
+      ->execute();
+
+    if ($existing) {
+      $this->thumbnail->target_id = reset($existing);
+    }
+    else {
+      /** @var \Drupal\file\FileInterface $file */
+      $file = $file_storage->create(['uri' => $thumbnail_uri]);
+      if ($owner = $this->getOwner()) {
+        $file->setOwner($owner);
+      }
+      $file->setPermanent();
+      $file->save();
+      $this->thumbnail->target_id = $file->id();
+    }
+
+    $this->thumbnail->alt = $this->t('Thumbnail');
+    $this->thumbnail->title = $this->label();
+
+    return $this;
+  }
+
+  /**
+   * Gets a file URI for a media item.
+   *
+   * If thumbnail fetching should be queued then temporary use default
+   * thumbnail for new files or temporary keep existing thumbnail for
+   * updates.
+   * Immediately fetch a new thumbnail from the media source otherwise.
+   *
+   * @param bool $from_queue
+   *   Specifies whether the thumbnail is being fetched from the queue.
+   *
+   * @return \Drupal\media\MediaInterface
+   *   The file URI for the thumbnail of the media item.
+   */
+  protected function getThumbnailUri($from_queue) {
+    if ($this->bundle->entity->thumbnailDownloadsAreQueued() && $this->isNew()) {
+      $default_thumbnail_filename = $this->getSource()->getPluginDefinition()['default_thumbnail_filename'];
+      $thumbnail_uri = \Drupal::service('config.factory')->get('media.settings')->get('icon_base_uri') . '/' . $default_thumbnail_filename;
+    }
+    elseif ($this->bundle->entity->thumbnailDownloadsAreQueued() && !$from_queue) {
+      $thumbnail_uri = $this->get('thumbnail')->entity->getFileUri();
+    }
+    else {
+      $thumbnail_uri = $this->getSource()->getMetadata($this, $this->getSource()->getPluginDefinition()['thumbnail_uri_metadata_attribute']);
+    }
+
+    return $thumbnail_uri;
+  }
+
+  /**
    * Determines if the thumbnail should be updated for a media item.
    *
    * @param bool $is_new
@@ -180,7 +241,7 @@
 
     // Set thumbnail.
     if ($this->shouldUpdateThumbnail()) {
-      \Drupal::service('media.thumbnail_handler')->updateThumbnail($this);
+      $this->updateThumbnail();
     }
   }
 
diff -u b/core/modules/media/src/MediaInterface.php b/core/modules/media/src/MediaInterface.php
--- b/core/modules/media/src/MediaInterface.php
+++ b/core/modules/media/src/MediaInterface.php
@@ -42,2 +42,13 @@
 
+  /**
+   * Update the thumbnail for the media item.
+   *
+   * @param bool $from_queue
+   *   Specifies whether the thumbnail is being fetched from the queue.
+   *
+   * @return \Drupal\media\MediaInterface
+   *   The updated media item.
+   */
+  public function updateThumbnail($from_queue = FALSE);
+
 }
reverted:
--- b/core/modules/media/src/MediaThumbnailHandler.php
+++ /dev/null
@@ -1,107 +0,0 @@
-<?php
-
-namespace Drupal\media;
-
-use Drupal\Core\Config\ConfigFactoryInterface;
-use Drupal\Core\Entity\EntityTypeManagerInterface;
-use Drupal\Core\StringTranslation\StringTranslationTrait;
-use Drupal\Core\StringTranslation\TranslationInterface;
-
-/**
- * Provides a service for handling media item thumbnails.
- */
-class MediaThumbnailHandler implements MediaThumbnailHandlerInterface {
-
-  use StringTranslationTrait;
-
-  /**
-   * The file entity storage handler.
-   *
-   * @var \Drupal\file\FileStorageInterface
-   */
-  protected $fileStorage;
-
-  /**
-   * The config factory service.
-   *
-   * @var \Drupal\Core\Config\ConfigFactoryInterface
-   */
-  protected $configFactory;
-
-  /**
-   * Constructs a new MediaThumbnailHandler.
-   *
-   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
-   *   The entity type manager service.
-   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
-   *   The string translation service.
-   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
-   *   The config factory service.
-   */
-  public function __construct(EntityTypeManagerInterface $entity_type_manager, TranslationInterface $translation, ConfigFactoryInterface $config_factory) {
-    $this->fileStorage = $entity_type_manager->getStorage('file');
-    $this->stringTranslation = $translation;
-    $this->configFactory = $config_factory;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function updateThumbnail(MediaInterface $media, $from_queue = FALSE) {
-    $thumbnail_uri = $this->getThumbnailUri($media, $from_queue);
-    $existing = $this->fileStorage->getQuery()
-      ->condition('uri', $thumbnail_uri)
-      ->execute();
-
-    if ($existing) {
-      $media->thumbnail->target_id = reset($existing);
-    }
-    else {
-      /** @var \Drupal\file\FileInterface $file */
-      $file = $this->fileStorage->create(['uri' => $thumbnail_uri]);
-      if ($owner = $media->getOwner()) {
-        $file->setOwner($owner);
-      }
-      $file->setPermanent();
-      $file->save();
-      $media->thumbnail->target_id = $file->id();
-    }
-
-    $media->thumbnail->alt = $this->t('Thumbnail');
-    $media->thumbnail->title = $media->label();
-
-    return $media;
-  }
-
-  /**
-   * Gets a file URI for a media item.
-   *
-   * If thumbnail fetching should be queued then temporary use default
-   * thumbnail for new files or temporary keep existing thumbnail for
-   * updates.
-   * Immediately fetch a new thumbnail from the media source otherwise.
-   *
-   * @param \Drupal\media\MediaInterface $media
-   *   A media item.
-   * @param bool $from_queue
-   *   Specifies whether the thumbnail is being fetched from the queue.
-   *
-   * @return \Drupal\media\MediaInterface
-   *   The file URI for the thumbnail of the media item.
-   */
-  protected function getThumbnailUri(MediaInterface $media, $from_queue) {
-    if ($media->bundle->entity->thumbnailDownloadsAreQueued() && $media->isNew()) {
-      $default_thumbnail_filename = $media->getSource()->getPluginDefinition()['default_thumbnail_filename'];
-      $thumbnail_uri = $this->configFactory->get('media.settings')->get('icon_base_uri') . '/' . $default_thumbnail_filename;
-    }
-    elseif ($media->bundle->entity->thumbnailDownloadsAreQueued() && !$from_queue) {
-      $thumbnail_uri = $media->get('thumbnail')->entity->getFileUri();
-    }
-    else {
-      $thumbnail_uri = $media->getSource()->getMetadata($media, $media->getSource()->getPluginDefinition()['thumbnail_uri_metadata_attribute']);
-    }
-
-    return $thumbnail_uri;
-  }
-
-}
reverted:
--- b/core/modules/media/src/MediaThumbnailHandlerInterface.php
+++ /dev/null
@@ -1,23 +0,0 @@
-<?php
-
-namespace Drupal\media;
-
-/**
- * Provides an interface for a service handling media thumbnails.
- */
-interface MediaThumbnailHandlerInterface {
-
-  /**
-   * Update the thumbnail for a media item.
-   *
-   * @param \Drupal\media\MediaInterface $media
-   *   A media item.
-   * @param bool $from_queue
-   *   Specifies whether the thumbnail is being fetched from the queue.
-   *
-   * @return \Drupal\media\MediaInterface
-   *   The changed media item.
-   */
-  public function updateThumbnail(MediaInterface $media, $from_queue = FALSE);
-
-}
diff -u b/core/modules/media/src/Plugin/QueueWorker/ThumbnailDownloader.php b/core/modules/media/src/Plugin/QueueWorker/ThumbnailDownloader.php
--- b/core/modules/media/src/Plugin/QueueWorker/ThumbnailDownloader.php
+++ b/core/modules/media/src/Plugin/QueueWorker/ThumbnailDownloader.php
@@ -20,28 +20,10 @@
 class ThumbnailDownloader extends QueueWorkerBase implements ContainerFactoryPluginInterface {
 
   /**
-   * The thumbnail handler service.
-   *
-   * @var \Drupal\media\MediaThumbnailHandlerInterface
-   */
-  protected $thumbnailHandler;
-
-  /**
-   * Constructs a new ThumbnailDownloader object.
-   *
-   * @param array $configuration
-   *   A configuration array containing information about the plugin instance.
-   * @param string $plugin_id
-   *   The plugin_id for the plugin instance.
-   * @param mixed $plugin_definition
-   *   The plugin implementation definition.
-   * @param \Drupal\media\MediaThumbnailHandlerInterface $thumbnail_handler
-   *   The thumbnail handler service.
+   * {@inheritdoc}
    */
-  public function __construct(array $configuration, $plugin_id, $plugin_definition, MediaThumbnailHandlerInterface $thumbnail_handler) {
+  public function __construct(array $configuration, $plugin_id, $plugin_definition) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
-
-    $this->thumbnailHandler = $thumbnail_handler;
   }
 
   /**
@@ -51,8 +33,7 @@
     return new static(
       $configuration,
       $plugin_id,
-      $plugin_definition,
-      $container->get('media.thumbnail_handler')
+      $plugin_definition
     );
   }
 
@@ -60,10 +41,9 @@
    * {@inheritdoc}
    */
   public function processItem($data) {
-    /** @var \Drupal\media\MediaInterface $entity */
-    if ($entity = Media::load($data['id'])) {
-      $this->thumbnailHandler->updateThumbnail($entity, TRUE);
-      $entity->save();
+    if ($media = Media::load($data['id'])) {
+      $media->updateThumbnail(TRUE);
+      $media->save();
     }
   }
 
reverted:
--- b/core/modules/media/src/Tests/MediaCacheTagsTest.php
+++ /dev/null
@@ -1,80 +0,0 @@
-<?php
-
-namespace Drupal\media\Tests;
-
-use Drupal\Core\Entity\EntityInterface;
-use Drupal\media\Entity\Media;
-use Drupal\media\Entity\MediaType;
-use Drupal\system\Tests\Entity\EntityWithUriCacheTagsTestBase;
-use Drupal\Tests\media\Functional\MediaFunctionalTestTrait;
-use Drupal\user\Entity\Role;
-use Drupal\user\RoleInterface;
-
-/**
- * Tests the media entity's cache tags.
- *
- * @group media
- */
-class MediaCacheTagsTest extends EntityWithUriCacheTagsTestBase {
-
-  use MediaFunctionalTestTrait;
-
-  /**
-   * {@inheritdoc}
-   */
-  public static $modules = [
-    'media',
-    'media_test_source',
-  ];
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function setUp() {
-    parent::setUp();
-
-    // Give anonymous users permission to view media, so that we can
-    // verify the cache tags of cached versions of media items.
-    $user_role = Role::load(RoleInterface::ANONYMOUS_ID);
-    $user_role->grantPermission('view media');
-    $user_role->save();
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function createEntity() {
-    // Create a media type.
-    $mediaType = $this->createMediaType();
-
-    // Create a media item.
-    $media = Media::create([
-      'bundle' => $mediaType->id(),
-      'name' => 'Unnamed',
-    ]);
-    $media->save();
-
-    return $media;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function getAdditionalCacheContextsForEntity(EntityInterface $media) {
-    return ['timezone'];
-  }
-
-  /**
-   * {@inheritdoc}
-   *
-   * Each media item must have an author and a thumbnail.
-   */
-  protected function getAdditionalCacheTagsForEntity(EntityInterface $media) {
-    return [
-      'user:' . $media->getOwnerId(),
-      'config:image.style.thumbnail',
-      'file:' . $media->get('thumbnail')->entity->id(),
-    ];
-  }
-
-}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/media/tests/src/Functional/MediaCacheTagsTest.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace Drupal\Tests\media\Functional;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\media\Entity\Media;
+use Drupal\system\Tests\Entity\EntityWithUriCacheTagsTestBase;
+use Drupal\user\Entity\Role;
+use Drupal\user\RoleInterface;
+
+/**
+ * Tests the media entity's cache tags.
+ *
+ * @group media
+ */
+class MediaCacheTagsTest extends EntityWithUriCacheTagsTestBase {
+
+  use MediaFunctionalTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = [
+    'media',
+    'media_test_source',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    // Give anonymous users permission to view media, so that we can
+    // verify the cache tags of cached versions of media items.
+    $user_role = Role::load(RoleInterface::ANONYMOUS_ID);
+    $user_role->grantPermission('view media');
+    $user_role->save();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function createEntity() {
+    // Create a media type.
+    $mediaType = $this->createMediaType();
+
+    // Create a media item.
+    $media = Media::create([
+      'bundle' => $mediaType->id(),
+      'name' => 'Unnamed',
+    ]);
+    $media->save();
+
+    return $media;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getAdditionalCacheContextsForEntity(EntityInterface $media) {
+    return ['timezone'];
+  }
+
+  /**
+   * {@inheritdoc}
+   *
+   * Each media item must have an author and a thumbnail.
+   */
+  protected function getAdditionalCacheTagsForEntity(EntityInterface $media) {
+    return [
+      'user:' . $media->getOwnerId(),
+      'config:image.style.thumbnail',
+      'file:' . $media->get('thumbnail')->entity->id(),
+    ];
+  }
+
+}