diff --git a/core/lib/Drupal/Core/Cache/Cache.php b/core/lib/Drupal/Core/Cache/Cache.php
index 82bb6a0..5ad9500 100644
--- a/core/lib/Drupal/Core/Cache/Cache.php
+++ b/core/lib/Drupal/Core/Cache/Cache.php
@@ -25,9 +25,9 @@ class Cache {
    * Merges arrays of cache contexts and removes duplicates.
    *
    * @param array $a
-   *    Cache context array to merge.
+   *    Cache contexts array to merge.
    * @param array $b
-   *    Cache context array to merge.
+   *    Cache contexts array to merge.
    *
    * @return string[]
    *   The merged array of cache contexts.
@@ -51,9 +51,9 @@ public static function mergeContexts(array $a = [], array $b = []) {
    * they're constituted from.
    *
    * @param array $a
-   *    Cache tag array to merge.
+   *    Cache tags array to merge.
    * @param array $b
-   *    Cache tag array to merge.
+   *    Cache tags array to merge.
    *
    * @return string[]
    *   The merged array of cache tags.
@@ -71,9 +71,9 @@ public static function mergeTags(array $a = [], array $b = []) {
    * Ensures infinite max-age (Cache::PERMANENT) is taken into account.
    *
    * @param int $a
-   *    Max age value to find.
+   *    Max age value to merge.
    * @param int $b
-   *    Max age value to find.
+   *    Max age value to merge.
    *
    * @return int
    *   The minimum max-age value.
diff --git a/core/modules/block/src/BlockViewBuilder.php b/core/modules/block/src/BlockViewBuilder.php
index 4266fd4..d7161d7 100644
--- a/core/modules/block/src/BlockViewBuilder.php
+++ b/core/modules/block/src/BlockViewBuilder.php
@@ -48,14 +48,8 @@ public function viewMultiple(array $entities = array(), $view_mode = 'full', $la
       $derivative_id = $plugin->getDerivativeId();
       $configuration = $plugin->getConfiguration();
 
-      $cache_tags = Cache::mergeTags(
-        $this->getCacheTags(),
-        $entity->getCacheTags()
-      );
-      $cache_tags = Cache::mergeTags(
-        $cache_tags,
-        $plugin->getCacheTags()
-      );
+      $cache_tags = Cache::mergeTags($this->getCacheTags(), $entity->getCacheTags());
+      $cache_tags = Cache::mergeTags($cache_tags, $plugin->getCacheTags());
 
       // Create the render array for the block as a whole.
       // @see template_preprocess_block().
diff --git a/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php b/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
index d4068f8..3c7b9d6 100644
--- a/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
+++ b/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
@@ -200,14 +200,8 @@ public function testEntityFormatter() {
 ';
     $renderer->renderRoot($build[0]);
     $this->assertEqual($build[0]['#markup'], 'default | ' . $this->referencedEntity->label() .  $expected_rendered_name_field_1 . $expected_rendered_body_field_1, sprintf('The markup returned by the %s formatter is correct for an item with a saved entity.', $formatter));
-    $expected_cache_tags = Cache::mergeTags(
-      \Drupal::entityManager()->getViewBuilder($this->entityType)->getCacheTags(),
-      $this->referencedEntity->getCacheTags()
-    );
-    $expected_cache_tags = Cache::mergeTags(
-      $expected_cache_tags,
-      FilterFormat::load('full_html')->getCacheTags()
-    );
+    $expected_cache_tags = Cache::mergeTags(\Drupal::entityManager()->getViewBuilder($this->entityType)->getCacheTags(), $this->referencedEntity->getCacheTags());
+    $expected_cache_tags = Cache::mergeTags($expected_cache_tags, FilterFormat::load('full_html')->getCacheTags());
     $this->assertEqual($build[0]['#cache']['tags'], $expected_cache_tags, format_string('The @formatter formatter has the expected cache tags.', array('@formatter' => $formatter)));
 
     // Test the second field item.
diff --git a/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php b/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
index 326103d..879ee7f 100644
--- a/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
+++ b/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
@@ -339,16 +339,13 @@ public function testReferencedEntity() {
     $entity_cache_contexts = $default_cache_contexts;
 
     // Cache tags present on every rendered page.
-    $page_cache_tags = Cache::mergeTags(
-      ['rendered'],
-      // 'user.permissions' is a required cache context, and responses that vary
-      // by this cache context when requested by anonymous users automatically
-      // also get this cache tag, to ensure correct invalidation.
-      ['config:user.role.anonymous'],
-      // If the block module is used, the Block page display variant is used,
-      // which adds the block config entity type's list cache tags.
-      \Drupal::moduleHandler()->moduleExists('block') ? ['config:block_list']: []
-    );
+    // 'user.permissions' is a required cache context, and responses that vary
+    // by this cache context when requested by anonymous users automatically
+    // also get this cache tag, to ensure correct invalidation.
+    // If the block module is used, the Block page display variant is used,
+    // which adds the block config entity type's list cache tags.
+    $page_cache_tags = Cache::mergeTags(['rendered', 'config:user.role.anonymous'], \Drupal::moduleHandler()->moduleExists('block') ? ['config:block_list']: []);
+
     $page_cache_tags_referencing_entity = in_array('user.permissions', $this->getAccessCacheContextsForEntity($this->referencingEntity)) ? ['config:user.role.anonymous'] : [];
 
     $view_cache_tag = array();
@@ -361,58 +358,25 @@ public function testReferencedEntity() {
     $cache_context_tags = $context_metadata->getCacheTags();
 
     // Generate the cache tags for the (non) referencing entities.
-    $referencing_entity_cache_tags = Cache::mergeTags(
-      $this->referencingEntity->getCacheTags(),
-      \Drupal::entityManager()->getViewBuilder('entity_test')->getCacheTags()
-    );
-    $referencing_entity_cache_tags = Cache::mergeTags(
-      $referencing_entity_cache_tags,
-      // Includes the main entity's cache tags, since this entity references it.
-      $this->entity->getCacheTags()
-    );
-    $referencing_entity_cache_tags = Cache::mergeTags(
-      $referencing_entity_cache_tags,
-      $this->getAdditionalCacheTagsForEntity($this->entity)
-    );
-    $referencing_entity_cache_tags = Cache::mergeTags(
-      $referencing_entity_cache_tags,
-      $view_cache_tag
-    );
-    $referencing_entity_cache_tags = Cache::mergeTags(
-      $referencing_entity_cache_tags,
-      $cache_context_tags,
-      ['rendered']
-    );
+    $referencing_entity_cache_tags = Cache::mergeTags($this->referencingEntity->getCacheTags(), \Drupal::entityManager()->getViewBuilder('entity_test')->getCacheTags());
+    // Includes the main entity's cache tags, since this entity references it.
+    $referencing_entity_cache_tags = Cache::mergeTags($referencing_entity_cache_tags, $this->entity->getCacheTags());
+    $referencing_entity_cache_tags = Cache::mergeTags($referencing_entity_cache_tags, $this->getAdditionalCacheTagsForEntity($this->entity));
+    $referencing_entity_cache_tags = Cache::mergeTags($referencing_entity_cache_tags, $view_cache_tag);
+    $referencing_entity_cache_tags = Cache::mergeTags($referencing_entity_cache_tags, $cache_context_tags);
+    $referencing_entity_cache_tags = Cache::mergeTags($referencing_entity_cache_tags, ['rendered']);
 
-    $non_referencing_entity_cache_tags = Cache::mergeTags(
-      $this->nonReferencingEntity->getCacheTags(),
-      \Drupal::entityManager()->getViewBuilder('entity_test')->getCacheTags()
-    );
-    $non_referencing_entity_cache_tags = Cache::mergeTags(
-      $non_referencing_entity_cache_tags,
-      ['rendered']
-    );
+    $non_referencing_entity_cache_tags = Cache::mergeTags($this->nonReferencingEntity->getCacheTags(), \Drupal::entityManager()->getViewBuilder('entity_test')->getCacheTags());
+    $non_referencing_entity_cache_tags = Cache::mergeTags($non_referencing_entity_cache_tags, ['rendered']);
 
     // Generate the cache tags for all two possible entity listing paths.
     // 1. list cache tag only (listing query has no match)
     // 2. list cache tag plus entity cache tag (listing query has a match)
-    $empty_entity_listing_cache_tags = Cache::mergeTags(
-      $this->entity->getEntityType()->getListCacheTags(),
-      $page_cache_tags
-    );
+    $empty_entity_listing_cache_tags = Cache::mergeTags($this->entity->getEntityType()->getListCacheTags(), $page_cache_tags);
 
-    $nonempty_entity_listing_cache_tags = Cache::mergeTags(
-      $this->entity->getEntityType()->getListCacheTags(),
-      $this->entity->getCacheTags()
-    );
-    $nonempty_entity_listing_cache_tags = Cache::mergeTags(
-      $nonempty_entity_listing_cache_tags,
-      $this->getAdditionalCacheTagsForEntityListing($this->entity)
-    );
-    $nonempty_entity_listing_cache_tags = Cache::mergeTags(
-      $nonempty_entity_listing_cache_tags,
-      $page_cache_tags
-    );
+    $nonempty_entity_listing_cache_tags = Cache::mergeTags($this->entity->getEntityType()->getListCacheTags(), $this->entity->getCacheTags());
+    $nonempty_entity_listing_cache_tags = Cache::mergeTags($nonempty_entity_listing_cache_tags, $this->getAdditionalCacheTagsForEntityListing($this->entity));
+    $nonempty_entity_listing_cache_tags = Cache::mergeTags($nonempty_entity_listing_cache_tags, $page_cache_tags);
 
     $this->pass("Test referencing entity.", 'Debug');
     $this->verifyPageCache($referencing_entity_url, 'MISS');
@@ -673,23 +637,11 @@ public function testReferencedEntity() {
     $this->verifyPageCache($non_referencing_entity_url, 'HIT');
 
     // Verify cache hits.
-    $referencing_entity_cache_tags = Cache::mergeTags(
-      $this->referencingEntity->getCacheTags(),
-      \Drupal::entityManager()->getViewBuilder('entity_test')->getCacheTags()
-    );
-    $referencing_entity_cache_tags = Cache::mergeTags(
-      $referencing_entity_cache_tags,
-      ['rendered']
-    );
+    $referencing_entity_cache_tags = Cache::mergeTags($this->referencingEntity->getCacheTags(), \Drupal::entityManager()->getViewBuilder('entity_test')->getCacheTags());
+    $referencing_entity_cache_tags = Cache::mergeTags($referencing_entity_cache_tags, ['rendered']);
 
-    $nonempty_entity_listing_cache_tags = Cache::mergeTags(
-      $this->entity->getEntityType()->getListCacheTags(),
-      $this->getAdditionalCacheTagsForEntityListing()
-    );
-    $nonempty_entity_listing_cache_tags = Cache::mergeTags(
-      $nonempty_entity_listing_cache_tags,
-      $page_cache_tags
-    );
+    $nonempty_entity_listing_cache_tags = Cache::mergeTags($this->entity->getEntityType()->getListCacheTags(), $this->getAdditionalCacheTagsForEntityListing());
+    $nonempty_entity_listing_cache_tags = Cache::mergeTags($nonempty_entity_listing_cache_tags, $page_cache_tags);
 
     $this->verifyPageCache($referencing_entity_url, 'HIT', Cache::mergeTags($referencing_entity_cache_tags, $page_cache_tags));
     $this->verifyPageCache($listing_url, 'HIT', $page_cache_tags);