diff -u b/core/lib/Drupal/Core/Menu/LocalTaskManager.php b/core/lib/Drupal/Core/Menu/LocalTaskManager.php
--- b/core/lib/Drupal/Core/Menu/LocalTaskManager.php
+++ b/core/lib/Drupal/Core/Menu/LocalTaskManager.php
@@ -334,8 +334,7 @@
           '#weight' => $child->getWeight(),
           '#access' => $access,
         ];
-        $cacheability->addCacheableDependency($access);
-        $cacheability->addCacheableDependency($child);
+        $cacheability->addCacheableDependency($access)->addCacheableDependency($child);
       }
     }
 
reverted:
--- b/core/modules/comment/src/Plugin/Menu/LocalTask/UnapprovedComments.php
+++ a/core/modules/comment/src/Plugin/Menu/LocalTask/UnapprovedComments.php
@@ -8,8 +8,6 @@
 namespace Drupal\comment\Plugin\Menu\LocalTask;
 
 use Drupal\comment\CommentStorageInterface;
-use Drupal\Core\Cache\Cache;
-use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Menu\LocalTaskDefault;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
diff -u b/core/modules/contact/contact.module b/core/modules/contact/contact.module
--- b/core/modules/contact/contact.module
+++ b/core/modules/contact/contact.module
@@ -5,8 +5,8 @@
  * Enables the use of personal and site-wide contact forms.
  */
 
+use Drupal\Core\Cache\RefinableCacheableDependencyInterface;
 use Drupal\Core\Form\FormStateInterface;
-use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\user\Entity\User;
 
@@ -99,7 +99,7 @@
  * Hides the 'Contact' tab on the user profile if the user does not have an
  * email address configured.
  */
-function contact_menu_local_tasks_alter(&$data, $route_name, CacheableMetadata &$cacheable_metadata) {
+function contact_menu_local_tasks_alter(&$data, $route_name) {
   if ($route_name == 'entity.user.canonical') {
     foreach ($data['tabs'][0] as $href => $tab_data) {
       if ($href == 'entity.user.contact_form') {
diff -u b/core/modules/system/tests/modules/menu_test/menu_test.module b/core/modules/system/tests/modules/menu_test/menu_test.module
--- b/core/modules/system/tests/modules/menu_test/menu_test.module
+++ b/core/modules/system/tests/modules/menu_test/menu_test.module
@@ -5,6 +5,7 @@
  * Module that implements various hooks for menu tests.
  */
 
+use Drupal\Core\Cache\RefinableCacheableDependencyInterface;
 use Drupal\Core\Url;
 
 /**
@@ -29,7 +30,7 @@
 /**
  * Implements hook_menu_local_tasks_alter().
  */
-function menu_test_menu_local_tasks_alter(&$data, $route_name, \Drupal\Core\Cache\RefinableCacheableDependencyInterface &$cacheability) {
+function menu_test_menu_local_tasks_alter(&$data, $route_name, RefinableCacheableDependencyInterface &$cacheability) {
   if (in_array($route_name, array('menu_test.tasks_default'))) {
     $data['tabs'][0]['foo'] = array(
       '#theme' => 'menu_local_task',
diff -u b/core/modules/system/tests/modules/menu_test/src/Plugin/Menu/LocalTask/TestTasksSettingsSub1.php b/core/modules/system/tests/modules/menu_test/src/Plugin/Menu/LocalTask/TestTasksSettingsSub1.php
--- b/core/modules/system/tests/modules/menu_test/src/Plugin/Menu/LocalTask/TestTasksSettingsSub1.php
+++ b/core/modules/system/tests/modules/menu_test/src/Plugin/Menu/LocalTask/TestTasksSettingsSub1.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\menu_test\Plugin\Menu\LocalTask;
 
-use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Menu\LocalTaskDefault;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 
diff -u b/core/tests/Drupal/Tests/Core/Menu/LocalTaskDefaultTest.php b/core/tests/Drupal/Tests/Core/Menu/LocalTaskDefaultTest.php
--- b/core/tests/Drupal/Tests/Core/Menu/LocalTaskDefaultTest.php
+++ b/core/tests/Drupal/Tests/Core/Menu/LocalTaskDefaultTest.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\Tests\Core\Menu;
 
-use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Menu\LocalTaskDefault;
 use Drupal\Core\Routing\RouteMatch;
 use Drupal\Core\Routing\RouteProviderInterface;
diff -u b/core/tests/Drupal/Tests/Core/Menu/LocalTaskManagerTest.php b/core/tests/Drupal/Tests/Core/Menu/LocalTaskManagerTest.php
--- b/core/tests/Drupal/Tests/Core/Menu/LocalTaskManagerTest.php
+++ b/core/tests/Drupal/Tests/Core/Menu/LocalTaskManagerTest.php
@@ -417,12 +417,12 @@
       ->method('getDefinitions')
       ->will($this->returnValue($definitions));
 
-    // Setup some cacheablity metadata and ensure its merged together.
+    // Set up some cacheablity metadata and ensure its merged together.
     $definitions['menu_local_task_test_tasks_settings']['cache_tags'] = ['tag.example1'];
     $definitions['menu_local_task_test_tasks_settings']['cache_contexts'] = ['context.example1'];
     $definitions['menu_local_task_test_tasks_edit']['cache_tags'] = ['tag.example2'];
     $definitions['menu_local_task_test_tasks_edit']['cache_contexts'] = ['context.example2'];
-    // Test the cacheable metadata of access checking.
+    // Test the cacheability metadata of access checking.
     $definitions['menu_local_task_test_tasks_view_child1']['access'] = AccessResult::allowed()->addCacheContexts(['user.permissions']);
 
     $this->setupFactoryAndLocalTaskPlugins($definitions, 'menu_local_task_test_tasks_view');
@@ -439,12 +439,12 @@
       ->method('getRawParameters')
       ->willReturn(new ParameterBag());
 
-    $cacheable_metadata = new CacheableMetadata();
-    $local_tasks = $this->manager->getTasksBuild('menu_local_task_test_tasks_view', $cacheable_metadata);
+    $cacheability = new CacheableMetadata();
+    $local_tasks = $this->manager->getTasksBuild('menu_local_task_test_tasks_view', $cacheability);
 
-    // Ensure that all cacheable metadata is merged together.
-    $this->assertEquals(['tag.example1', 'tag.example2'], $cacheable_metadata->getCacheTags());
-    $this->assertEquals(['context.example1', 'context.example2', 'route', 'user.permissions'], $cacheable_metadata->getCacheContexts());
+    // Ensure that all cacheability metadata is merged together.
+    $this->assertEquals(['tag.example1', 'tag.example2'], $cacheability->getCacheTags());
+    $this->assertEquals(['context.example1', 'context.example2', 'route', 'user.permissions'], $cacheability->getCacheContexts());
  }
 
   protected function setupFactoryAndLocalTaskPlugins(array $definitions, $active_plugin_id) {