diff -u b/core/lib/Drupal/Core/Cache/Context/AccountPermissionsCacheContext.php b/core/lib/Drupal/Core/Cache/Context/AccountPermissionsCacheContext.php
--- b/core/lib/Drupal/Core/Cache/Context/AccountPermissionsCacheContext.php
+++ b/core/lib/Drupal/Core/Cache/Context/AccountPermissionsCacheContext.php
@@ -55,6 +55,7 @@
   * {@inheritdoc}
   */
   public function getCacheTags() {
+    $tags = [];
     foreach ($this->user->getRoles() as $role) {
       $tags[] = "config:user.role.$role";
     }
diff -u b/core/lib/Drupal/Core/Cache/Context/CacheContextsManager.php b/core/lib/Drupal/Core/Cache/Context/CacheContextsManager.php
--- b/core/lib/Drupal/Core/Cache/Context/CacheContextsManager.php
+++ b/core/lib/Drupal/Core/Cache/Context/CacheContextsManager.php
@@ -113,7 +113,7 @@
       list($context_id, $parameter) = $context_token;
       $context = $this->getService($context_id);
       if ($context instanceof CacheableCacheContextInterface || $context instanceof CacheableCalculatedCacheContextInterface) {
-        $cacheable_metadata->addCacheTags($context->getCacheableMetadata()->getCacheTags());
+        $cacheable_metadata = $cacheable_metadata->merge(CacheableMetadata::createFromObject($context->getCacheableMetadata()));
       }
     }
 
diff -u b/core/lib/Drupal/Core/Render/RenderCache.php b/core/lib/Drupal/Core/Render/RenderCache.php
--- b/core/lib/Drupal/Core/Render/RenderCache.php
+++ b/core/lib/Drupal/Core/Render/RenderCache.php
@@ -306,10 +306,9 @@
       if (!empty($elements['#cache']['contexts'])) {
         $contexts = $this->cacheContextsManager->convertTokensToKeys($elements['#cache']['contexts']);
         $cid_parts = array_merge($cid_parts, $contexts['contexts']);
-        if (!isset($elements['#cache']['tags'])) {
-          $elements['#cache']['tags'] = [];
-        }
-        $elements['#cache']['tags'] = Cache::mergeTags($elements['#cache']['tags'], $contexts['cacheable_metadata']->getCacheTags());
+        CacheableMetadata::createFromRenderArray($elements)
+          ->merge($contexts['cacheable_metadata'])
+          ->applyTo($elements);
       }
       return implode(':', $cid_parts);
     }
only in patch2:
unchanged:
--- a/core/modules/comment/src/Tests/CommentCacheTagsTest.php
+++ b/core/modules/comment/src/Tests/CommentCacheTagsTest.php
@@ -102,6 +102,7 @@ protected function getAdditionalCacheTagsForEntity(EntityInterface $entity) {
     /** @var \Drupal\comment\CommentInterface $entity */
     return array(
       'config:filter.format.plain_text',
+      'config:user.role.anonymous',
       'user:' . $entity->getOwnerId(),
       'user_view',
     );
only in patch2:
unchanged:
--- a/core/modules/comment/src/Tests/CommentDefaultFormatterCacheTagsTest.php
+++ b/core/modules/comment/src/Tests/CommentDefaultFormatterCacheTagsTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\comment\Tests;
 
+use Drupal\Core\Cache\Cache;
 use Drupal\Core\Session\UserSession;
 use Drupal\comment\CommentInterface;
 use Drupal\system\Tests\Entity\EntityUnitTestBase;
@@ -69,7 +70,8 @@ public function testCacheTags() {
       ->getViewBuilder('entity_test')
       ->view($commented_entity);
     $renderer->renderRoot($build);
-    $expected_cache_tags = array(
+    $cache_context_tags = \Drupal::service('cache_contexts_manager')->convertTokensToKeys($build['#cache']['contexts'])['cacheable_metadata']->getCacheTags();
+    $expected_cache_tags = Cache::mergeTags($cache_context_tags, [
       'entity_test_view',
       'entity_test:'  . $commented_entity->id(),
       'comment_list',
@@ -78,9 +80,9 @@ public function testCacheTags() {
       'config:field.field.entity_test.entity_test.comment',
       'config:field.storage.comment.comment_body',
       'config:user.settings',
-    );
+    ]);
     sort($expected_cache_tags);
-    $this->assertEqual($build['#cache']['tags'], $expected_cache_tags, 'The test entity has the expected cache tags before it has comments.');
+    $this->assertEqual($build['#cache']['tags'], $expected_cache_tags);
 
     // Create a comment on that entity. Comment loading requires that the uid
     // also exists in the {users} table.
@@ -111,7 +113,8 @@ public function testCacheTags() {
       ->getViewBuilder('entity_test')
       ->view($commented_entity);
     $renderer->renderRoot($build);
-    $expected_cache_tags = array(
+    $cache_context_tags = \Drupal::service('cache_contexts_manager')->convertTokensToKeys($build['#cache']['contexts'])['cacheable_metadata']->getCacheTags();
+    $expected_cache_tags = Cache::mergeTags($cache_context_tags, [
       'entity_test_view',
       'entity_test:' . $commented_entity->id(),
       'comment_list',
@@ -125,9 +128,9 @@ public function testCacheTags() {
       'config:field.field.entity_test.entity_test.comment',
       'config:field.storage.comment.comment_body',
       'config:user.settings',
-    );
+    ]);
     sort($expected_cache_tags);
-    $this->assertEqual($build['#cache']['tags'], $expected_cache_tags, 'The test entity has the expected cache tags when it has comments.');
+    $this->assertEqual($build['#cache']['tags'], $expected_cache_tags);
   }
 
 }
only in patch2:
unchanged:
--- a/core/modules/comment/src/Tests/CommentRssTest.php
+++ b/core/modules/comment/src/Tests/CommentRssTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\comment\Tests;
 
 use Drupal\comment\Plugin\Field\FieldType\CommentItemInterface;
+use Drupal\Core\Cache\Cache;
 use Drupal\Core\Entity\Entity\EntityViewDisplay;
 use Drupal\system\Tests\Cache\AssertPageCacheContextsAndTagsTrait;
 
@@ -52,16 +53,22 @@ function testCommentRss() {
     $this->postComment($this->node, $this->randomMachineName(), $this->randomMachineName());
     $this->drupalGet('rss.xml');
 
-    $this->assertCacheTags([
-      'config:views.view.frontpage', 'node:1', 'node_list', 'node_view', 'user:3',
-    ]);
-    $this->assertCacheContexts([
+    $cache_contexts = [
       'languages:language_interface',
       'theme',
       'user.node_grants:view',
       'user.permissions',
       'timezone',
-    ]);
+    ];
+    $this->assertCacheContexts($cache_contexts);
+
+    $cache_context_tags = \Drupal::service('cache_contexts_manager')->convertTokensToKeys($cache_contexts)['cacheable_metadata']->getCacheTags();
+    $this->assertCacheTags(Cache::mergeTags($cache_context_tags, [
+      'config:views.view.frontpage',
+      'node:1', 'node_list',
+      'node_view',
+      'user:3',
+    ]));
 
     $raw = '<comments>' . $this->node->url('canonical', array('fragment' => 'comments', 'absolute' => TRUE)) . '</comments>';
     $this->assertRaw($raw, 'Comments as part of RSS feed.');
only in patch2:
unchanged:
--- a/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
+++ b/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
@@ -203,7 +203,8 @@ public function testEntityFormatter() {
     $expected_cache_tags = Cache::mergeTags(
       \Drupal::entityManager()->getViewBuilder($this->entityType)->getCacheTags(),
       $this->referencedEntity->getCacheTags(),
-      FilterFormat::load('full_html')->getCacheTags()
+      FilterFormat::load('full_html')->getCacheTags(),
+      ['config:user.role.anonymous']
     );
     $this->assertEqual($build[0]['#cache']['tags'], $expected_cache_tags, format_string('The @formatter formatter has the expected cache tags.', array('@formatter' => $formatter)));
 
only in patch2:
unchanged:
--- a/core/modules/node/src/Tests/Views/FrontPageTest.php
+++ b/core/modules/node/src/Tests/Views/FrontPageTest.php
@@ -251,6 +251,8 @@ protected function assertFrontPageViewCacheTags($do_assert_views_caches) {
       'url.query_args.pagers:0',
     ];
 
+    $cache_context_tags = \Drupal::service('cache_contexts_manager')->convertTokensToKeys($cache_contexts)['cacheable_metadata']->getCacheTags();
+
     // Test before there are any nodes.
     $empty_node_listing_cache_tags = [
       'config:views.view.frontpage',
@@ -260,12 +262,12 @@ protected function assertFrontPageViewCacheTags($do_assert_views_caches) {
       $view,
       $empty_node_listing_cache_tags,
       $do_assert_views_caches,
-      $empty_node_listing_cache_tags
+      Cache::mergeTags($empty_node_listing_cache_tags, $cache_context_tags)
     );
     $this->assertPageCacheContextsAndTags(
       Url::fromRoute('view.frontpage.page_1'),
       $cache_contexts,
-      Cache::mergeTags($empty_node_listing_cache_tags, ['rendered', 'config:user.role.anonymous'])
+      Cache::mergeTags($empty_node_listing_cache_tags, $cache_context_tags, ['rendered', 'config:user.role.anonymous'])
     );
 
     // Create some nodes on the frontpage view. Add more than 10 nodes in order
@@ -307,12 +309,17 @@ protected function assertFrontPageViewCacheTags($do_assert_views_caches) {
       'node:14',
       'node:15',
     ];
-    $first_page_output_cache_tags = Cache::mergeTags($first_page_result_cache_tags, [
-      'config:filter.format.plain_text',
-      'node_view',
-      'user_view',
-      'user:0',
-    ]);
+    $cache_context_tags = \Drupal::service('cache_contexts_manager')->convertTokensToKeys($cache_contexts)['cacheable_metadata']->getCacheTags();
+    $first_page_output_cache_tags = Cache::mergeTags(
+      $first_page_result_cache_tags,
+      $cache_context_tags,
+      [
+        'config:filter.format.plain_text',
+        'node_view',
+        'user_view',
+        'user:0',
+      ]
+    );
     $view->setDisplay('page_1');
     $view->setCurrentPage(0);
     $this->assertViewsCacheTags(
only in patch2:
unchanged:
--- a/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
+++ b/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
@@ -349,6 +349,9 @@ public function testReferencedEntity() {
         ->getCacheTags();
     }
 
+    $context_metadata = \Drupal::service('cache_contexts_manager')->convertTokensToKeys($entity_cache_contexts)['cacheable_metadata'];
+    $cache_context_tags = $context_metadata->getCacheTags();
+
     // Generate the cache tags for the (non) referencing entities.
     $referencing_entity_cache_tags = Cache::mergeTags(
       $this->referencingEntity->getCacheTags(),
@@ -357,6 +360,7 @@ public function testReferencedEntity() {
       $this->entity->getCacheTags(),
       $this->getAdditionalCacheTagsForEntity($this->entity),
       $view_cache_tag,
+      $cache_context_tags,
       ['rendered']
     );
     $non_referencing_entity_cache_tags = Cache::mergeTags(
@@ -389,7 +393,10 @@ public function testReferencedEntity() {
     $access_cache_contexts = $this->getAccessCacheContextsForEntity($this->entity);
     $redirected_cid = NULL;
     if (count($access_cache_contexts)) {
-      $redirected_cid = $this->createCacheId($cache_keys, Cache::mergeContexts($entity_cache_contexts, $this->getAdditionalCacheContextsForEntity($this->referencingEntity), $access_cache_contexts));
+      $cache_contexts = Cache::mergeContexts($entity_cache_contexts, $this->getAdditionalCacheContextsForEntity($this->referencingEntity), $access_cache_contexts);
+      $redirected_cid = $this->createCacheId($cache_keys, $cache_contexts);
+      $context_metadata = \Drupal::service('cache_contexts_manager')->convertTokensToKeys($cache_contexts)['cacheable_metadata'];
+      $referencing_entity_cache_tags = Cache::mergeTags($referencing_entity_cache_tags, $context_metadata->getCacheTags());
     }
     $this->verifyRenderCache($cid, $referencing_entity_cache_tags, $redirected_cid);
 
@@ -653,7 +660,7 @@ protected function createCacheId(array $keys, array $contexts) {
     $cid_parts = $keys;
 
     $contexts = \Drupal::service('cache_contexts_manager')->convertTokensToKeys($contexts);
-    $cid_parts = array_merge($cid_parts, $contexts);
+    $cid_parts = array_merge($cid_parts, $contexts['contexts']);
 
     return implode(':', $cid_parts);
   }
only in patch2:
unchanged:
--- a/core/modules/system/src/Tests/Entity/EntityViewBuilderTest.php
+++ b/core/modules/system/src/Tests/Entity/EntityViewBuilderTest.php
@@ -65,7 +65,7 @@ public function testEntityViewBuilderCache() {
     // Get a fully built entity view render array.
     $entity_test->save();
     $build = $this->container->get('entity.manager')->getViewBuilder('entity_test')->view($entity_test, 'full');
-    $cid_parts = array_merge($build['#cache']['keys'], $cache_contexts_manager->convertTokensToKeys(['languages:' . LanguageInterface::TYPE_INTERFACE, 'theme']));
+    $cid_parts = array_merge($build['#cache']['keys'], $cache_contexts_manager->convertTokensToKeys(['languages:' . LanguageInterface::TYPE_INTERFACE, 'theme'])['contexts']);
     $cid = implode(':', $cid_parts);
     $bin = $build['#cache']['bin'];
 
@@ -117,7 +117,7 @@ public function testEntityViewBuilderCacheWithReferences() {
 
     // Get a fully built entity view render array for the referenced entity.
     $build = $this->container->get('entity.manager')->getViewBuilder('entity_test')->view($entity_test_reference, 'full');
-    $cid_parts = array_merge($build['#cache']['keys'], $cache_contexts_manager->convertTokensToKeys(['languages:' . LanguageInterface::TYPE_INTERFACE, 'theme']));
+    $cid_parts = array_merge($build['#cache']['keys'], $cache_contexts_manager->convertTokensToKeys(['languages:' . LanguageInterface::TYPE_INTERFACE, 'theme'])['contexts']);
     $cid_reference = implode(':', $cid_parts);
     $bin_reference = $build['#cache']['bin'];
 
@@ -136,7 +136,7 @@ public function testEntityViewBuilderCacheWithReferences() {
 
     // Get a fully built entity view render array.
     $build = $this->container->get('entity.manager')->getViewBuilder('entity_test')->view($entity_test, 'full');
-    $cid_parts = array_merge($build['#cache']['keys'], $cache_contexts_manager->convertTokensToKeys(['languages:' . LanguageInterface::TYPE_INTERFACE, 'theme']));
+    $cid_parts = array_merge($build['#cache']['keys'], $cache_contexts_manager->convertTokensToKeys(['languages:' . LanguageInterface::TYPE_INTERFACE, 'theme'])['contexts']);
     $cid = implode(':', $cid_parts);
     $bin = $build['#cache']['bin'];
 
only in patch2:
unchanged:
--- a/core/modules/system/tests/modules/pager_test/src/Controller/PagerTestController.php
+++ b/core/modules/system/tests/modules/pager_test/src/Controller/PagerTestController.php
@@ -69,7 +69,7 @@ public function queryParameters() {
    * #pre_render callback for #type => pager that shows the pager cache context.
    */
   public static function showPagerCacheContext(array $pager) {
-    drupal_set_message(\Drupal::service('cache_contexts_manager')->convertTokensToKeys(['url.query_args.pagers:' . $pager['#element']])[0]);
+    drupal_set_message(\Drupal::service('cache_contexts_manager')->convertTokensToKeys(['url.query_args.pagers:' . $pager['#element']])['contexts'][0]);
     return $pager;
   }
 
only in patch2:
unchanged:
--- a/core/tests/Drupal/Tests/Core/Render/RendererTestBase.php
+++ b/core/tests/Drupal/Tests/Core/Render/RendererTestBase.php
@@ -8,6 +8,7 @@
 namespace Drupal\Tests\Core\Render;
 
 use Drupal\Core\Cache\Cache;
+use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Cache\MemoryBackend;
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\Render\Element;
@@ -124,7 +125,7 @@ protected function setUp() {
               $keys[] = $context_id;
           }
         }
-        return $keys;
+        return ['contexts' => $keys, 'cacheable_metadata' => new CacheableMetadata()];
       });
     $this->renderCache = new RenderCache($this->requestStack, $this->cacheFactory, $this->cacheContextsManager);
     $this->renderer = new Renderer($this->controllerResolver, $this->themeManager, $this->elementInfo, $this->renderCache, $this->rendererConfig);