diff --git a/core/modules/comment/lib/Drupal/comment/CommentManager.php b/core/modules/comment/lib/Drupal/comment/CommentManager.php
index e144fb4..893333d 100644
--- a/core/modules/comment/lib/Drupal/comment/CommentManager.php
+++ b/core/modules/comment/lib/Drupal/comment/CommentManager.php
@@ -329,10 +329,10 @@ public function forbiddenMessage(EntityInterface $entity, $field_name) {
   /**
    * {@inheritdoc}
    */
-  public function getCountNewComments(EntityInterface $entity, $field_name = NULL, $timestamp = 0, AccountInterface $account = NULL) {
+  public function getCountNewComments(EntityInterface $entity, $field_name = NULL, $timestamp = 0) {
     // @todo Replace module handler with optional history service injection
     //   after http://drupal.org/node/2081585
-    if (\Drupal::currentUser()->isAuthenticated() && \Drupal::moduleHandler()->moduleExists('history')) {
+    if ($this->currentUser->isAuthenticated() && \Drupal::moduleHandler()->moduleExists('history')) {
       // Retrieve the timestamp at which the current user last viewed this entity.
       if (!$timestamp) {
         if ($entity->entityType() == 'node') {
diff --git a/core/modules/comment/lib/Drupal/comment/CommentManagerInterface.php b/core/modules/comment/lib/Drupal/comment/CommentManagerInterface.php
index e5a8f1d..c83f5ae 100644
--- a/core/modules/comment/lib/Drupal/comment/CommentManagerInterface.php
+++ b/core/modules/comment/lib/Drupal/comment/CommentManagerInterface.php
@@ -117,13 +117,10 @@ public function forbiddenMessage(EntityInterface $entity, $field_name);
    *   The field_name to count comments for. Defaults to any field.
    * @param int $timestamp
    *   Time to count from. Defaults to time of last user access the entity.
-   * @param \Drupal\Core\Session\AccountInterface $account
-   *   The user for which to count the new comments. Defaults to the current
-   *   user.
    *
    * @return int|false
    *   The number of new comments or FALSE if the user is not authenticated.
    */
-  public function getCountNewComments(EntityInterface $entity, $field_name = NULL, $timestamp = 0, AccountInterface $account = NULL);
+  public function getCountNewComments(EntityInterface $entity, $field_name = NULL, $timestamp = 0);
 
 }
diff --git a/core/modules/forum/tests/Drupal/forum/Tests/ForumManagerTest.php b/core/modules/forum/tests/Drupal/forum/Tests/ForumManagerTest.php
index 1626e19..ee52b0a 100644
--- a/core/modules/forum/tests/Drupal/forum/Tests/ForumManagerTest.php
+++ b/core/modules/forum/tests/Drupal/forum/Tests/ForumManagerTest.php
@@ -9,12 +9,6 @@
 
 use Drupal\Tests\UnitTestCase;
 
-// @todo Remove once the constants are replaced with constants on classes.
-//   https://drupal.org/node/2169361
-if (!defined('COMMENT_OPEN')) {
-  define('COMMENT_OPEN', 2);
-}
-
 /**
  * Tests the ForumManager.
  *