.../modules/media/src/Plugin/Filter/MediaEmbed.php | 39 ++++++++++------------
 .../media/tests/src/Functional/FilterTest.php      |  6 ++--
 2 files changed, 20 insertions(+), 25 deletions(-)

diff --git a/core/modules/media/src/Plugin/Filter/MediaEmbed.php b/core/modules/media/src/Plugin/Filter/MediaEmbed.php
index 4cfd796..bdb6806 100644
--- a/core/modules/media/src/Plugin/Filter/MediaEmbed.php
+++ b/core/modules/media/src/Plugin/Filter/MediaEmbed.php
@@ -24,40 +24,35 @@
  * @Filter(
  *   id = "media_embed",
  *   title = @Translation("Embed media"),
- *   description = @Translation("Embeds media items entities using a custom HTML tag. If used in conjunction with the 'Align/Caption' filters, make sure this filter is configured to run before them."),
+ *   description = @Translation("Embeds media items using a custom HTML tag. If used in conjunction with the 'Align/Caption' filters, make sure this filter is configured to run after them."),
  *   type = Drupal\filter\Plugin\FilterInterface::TYPE_TRANSFORM_REVERSIBLE,
  *   weight = 100,
  * )
+ *
+ * @internal
  */
-class MediaEmbed extends FilterBase implements ContainerFactoryPluginInterface {
-
-  /**
-   * The entity type supported by this filter.
-   *
-   * @var string
-   */
-  const ENTITY_TYPE_ID = 'media';
+final class MediaEmbed extends FilterBase implements ContainerFactoryPluginInterface {
 
   /**
    * The entity repository.
    *
    * @var \Drupal\Core\Entity\EntityRepositoryInterface
    */
-  protected $entityRepository;
+  private $entityRepository;
 
   /**
    * The entity type manager.
    *
    * @var \Drupal\Core\Entity\EntityTypeManagerInterface
    */
-  protected $entityTypeManager;
+  private $entityTypeManager;
 
   /**
    * The renderer.
    *
    * @var \Drupal\Core\Render\RendererInterface
    */
-  protected $renderer;
+  private $renderer;
 
   /**
    * Constructs a MediaEmbed object.
@@ -104,14 +99,14 @@ public static function create(ContainerInterface $container, array $configuratio
    * @param string $view_mode
    *   The view mode to render it in.
    * @param string $langcode
-   *   Language code in which the media entity must be rendered.
+   *   Language code in which the media entity should be rendered.
    *
    * @return array
    *   A render array.
    */
   private function renderMedia(MediaInterface $media, $view_mode, $langcode) {
     $build = $this->entityTypeManager
-      ->getViewBuilder(static::ENTITY_TYPE_ID)
+      ->getViewBuilder('media')
       ->view($media, $view_mode, $langcode);
 
     // The "embed" view mode already disabled render caching, but there are some
@@ -159,13 +154,13 @@ public function process($text, $langcode) {
       $xpath = new \DOMXPath($dom);
 
       foreach ($xpath->query('//drupal-media[@data-entity-type="media" and normalize-space(@data-view-mode)!="" and normalize-space(@data-entity-uuid)!=""]') as $node) {
-        $media = $this->entityRepository->loadEntityByUuid(static::ENTITY_TYPE_ID, $node->getAttribute('data-entity-uuid'));
+        $media = $this->entityRepository->loadEntityByUuid('media', $node->getAttribute('data-entity-uuid'));
         assert($media === NULL || $media instanceof MediaInterface);
         $view_mode = $node->getAttribute('data-view-mode');
 
-        $build = $media === NULL
-          ? $this->renderMissingMedia()
-          : $this->renderMedia($media, $view_mode, $langcode);
+        $build = $media
+          ? $this->renderMedia($media, $view_mode, $langcode)
+          : $this->renderMissingMedia();
 
         $this->renderIntoDomNode($build, $node, $result);
       }
@@ -197,15 +192,15 @@ public function tips($long = FALSE) {
   /**
    * Renders the given render array into the given DOM node.
    *
-   * @param array &$build
+   * @param array $build
    *   The render array to render in isolation
-   * @param \DOMElement &$node
-   *   The DOM node to render into. To be serialized later.
+   * @param \DOMNode &$node
+   *   The DOM node to render into.
    * @param \Drupal\filter\FilterProcessResult $result
    *   The accumulated result of filter processing, updated with the metadata
    *   bubbled during rendering.
    */
-  private function renderIntoDomNode(array $build, \DOMElement $node, FilterProcessResult &$result) {
+  private function renderIntoDomNode(array $build, \DOMNode $node, FilterProcessResult &$result) {
     // We need to render the embedded entity:
     // - without replacing placeholders, so that the placeholders are
     //   only replaced at the last possible moment. Hence we cannot use
diff --git a/core/modules/media/tests/src/Functional/FilterTest.php b/core/modules/media/tests/src/Functional/FilterTest.php
index 4f73ae5..65c8789 100644
--- a/core/modules/media/tests/src/Functional/FilterTest.php
+++ b/core/modules/media/tests/src/Functional/FilterTest.php
@@ -73,7 +73,7 @@ protected function setUp() {
     $media_type = $this->createMediaType('image');
 
     EntityViewMode::create([
-      'id' => 'media.embed',
+      'id' => 'media.foobar',
       'targetEntityType' => 'media',
       'status' => TRUE,
       'enabled' => TRUE,
@@ -83,7 +83,7 @@ protected function setUp() {
     EntityViewDisplay::create([
       'targetEntityType' => 'media',
       'bundle' => $media_type->id(),
-      'mode' => 'embed',
+      'mode' => 'foobar',
       'status' => TRUE,
     ])->removeComponent('thumbnail')
       ->removeComponent('created')
@@ -120,7 +120,7 @@ protected function setUp() {
    * are passed. Also tests situations when embed fails.
    */
   public function testFilter() {
-    $content = '<drupal-media data-entity-type="media" data-entity-uuid="' . $this->media->uuid() . '" data-view-mode="embed">This placeholder should not be rendered.</drupal-media>';
+    $content = '<drupal-media data-entity-type="media" data-entity-uuid="' . $this->media->uuid() . '" data-view-mode="foobar">This placeholder should not be rendered.</drupal-media>';
     $settings = [];
     $settings['type'] = 'page';
     $settings['title'] = 'Test entity embed with entity-id and view-mode';