diff --git a/core/includes/common.inc b/core/includes/common.inc
index 8444244..bb2ad11 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -658,7 +658,7 @@ function drupal_js_defaults($data = NULL) {
  *   \Drupal\Core\Render\Renderer::mergeAttachments() instead.
  */
 function drupal_merge_attached(array $a, array $b) {
-  return Renderer::mergeAttachments($a, $b);
+  return \Drupal::service('renderer')->mergeAttachments($a, $b);
 }
 
 /**
diff --git a/core/lib/Drupal/Core/Ajax/AjaxResponse.php b/core/lib/Drupal/Core/Ajax/AjaxResponse.php
index 1bc3d7e..2c7b9f0 100644
--- a/core/lib/Drupal/Core/Ajax/AjaxResponse.php
+++ b/core/lib/Drupal/Core/Ajax/AjaxResponse.php
@@ -78,7 +78,7 @@ public function addCommand(CommandInterface $command, $prepend = FALSE) {
         'library' => $assets->getLibraries(),
         'drupalSettings' => $assets->getSettings(),
       ];
-      $attachments = Renderer::mergeAttachments($this->attachments, $attachments);
+      $attachments = \Drupal::service('renderer')->mergeAttachments($this->attachments, $attachments);
       $this->setAttachments($attachments);
     }
 
diff --git a/core/lib/Drupal/Core/Render/BubbleableMetadata.php b/core/lib/Drupal/Core/Render/BubbleableMetadata.php
index d822d82..7c4401a 100644
--- a/core/lib/Drupal/Core/Render/BubbleableMetadata.php
+++ b/core/lib/Drupal/Core/Render/BubbleableMetadata.php
@@ -70,7 +70,7 @@ public function merge(BubbleableMetadata $other) {
     $result->contexts = Cache::mergeContexts($this->contexts, $other->contexts);
     $result->tags = Cache::mergeTags($this->tags, $other->tags);
     $result->maxAge = Cache::mergeMaxAges($this->maxAge, $other->maxAge);
-    $result->attached = Renderer::mergeAttachments($this->attached, $other->attached);
+    $result->attached = \Drupal::service('renderer')->mergeAttachments($this->attached, $other->attached);
     $result->postRenderCache = NestedArray::mergeDeep($this->postRenderCache, $other->postRenderCache);
     return $result;
   }
diff --git a/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php b/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php
index 249b47b..d12b18b 100644
--- a/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php
+++ b/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php
@@ -286,7 +286,7 @@ public function invokePageAttachmentHooks(array &$page) {
     }
 
     // Merge the attachments onto the $page render array.
-    $page = Renderer::mergeBubbleableMetadata($page, $attachments);
+    $page = $this->renderer->mergeBubbleableMetadata($page, $attachments);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Render/Renderer.php b/core/lib/Drupal/Core/Render/Renderer.php
index b1d300e..71d0ed8 100644
--- a/core/lib/Drupal/Core/Render/Renderer.php
+++ b/core/lib/Drupal/Core/Render/Renderer.php
@@ -757,7 +757,7 @@ public function getCacheableRenderArray(array $elements) {
   /**
    * {@inheritdoc}
    */
-  public static function mergeBubbleableMetadata(array $a, array $b) {
+  public function mergeBubbleableMetadata(array $a, array $b) {
     $meta_a = BubbleableMetadata::createFromRenderArray($a);
     $meta_b = BubbleableMetadata::createFromRenderArray($b);
     $meta_a->merge($meta_b)->applyTo($a);
@@ -767,7 +767,7 @@ public static function mergeBubbleableMetadata(array $a, array $b) {
   /**
    * {@inheritdoc}
    */
-  public static function mergeAttachments(array $a, array $b) {
+  public function mergeAttachments(array $a, array $b) {
     // If both #attached arrays contain drupalSettings, then merge them
     // correctly; adding the same settings multiple times needs to behave
     // idempotently.
diff --git a/core/lib/Drupal/Core/Render/RendererInterface.php b/core/lib/Drupal/Core/Render/RendererInterface.php
index 21b223d..98c013e 100644
--- a/core/lib/Drupal/Core/Render/RendererInterface.php
+++ b/core/lib/Drupal/Core/Render/RendererInterface.php
@@ -338,7 +338,7 @@ public function getCacheableRenderArray(array $elements);
    *
    * @see \Drupal\Core\Render\BubbleableMetadata
    */
-  public static function mergeBubbleableMetadata(array $a, array $b);
+  public function mergeBubbleableMetadata(array $a, array $b);
 
   /**
    * Merges two attachments arrays (which live under the '#attached' key).
@@ -382,7 +382,7 @@ public static function mergeBubbleableMetadata(array $a, array $b);
    * @return array
    *   The merged attachments array.
    */
-  public static function mergeAttachments(array $a, array $b);
+  public function mergeAttachments(array $a, array $b);
 
   /**
    * Generates a render cache placeholder.
diff --git a/core/modules/comment/src/CommentPostRenderCache.php b/core/modules/comment/src/CommentPostRenderCache.php
index 0348cc3..fd6fbc7 100644
--- a/core/modules/comment/src/CommentPostRenderCache.php
+++ b/core/modules/comment/src/CommentPostRenderCache.php
@@ -121,7 +121,7 @@ public function renderForm(array $element, array $context) {
     $callback = 'comment.post_render_cache:renderForm';
     $placeholder = $this->generatePlaceholder($callback, $context);
     $element['#markup'] = str_replace($placeholder, $markup, $element['#markup']);
-    $element = Renderer::mergeBubbleableMetadata($element, $form);
+    $element = $this->renderer->mergeBubbleableMetadata($element, $form);
 
     return $element;
   }