diff --git a/core/modules/user/lib/Drupal/user/Tests/UserPermissionsTest.php b/core/modules/user/lib/Drupal/user/Tests/UserPermissionsTest.php
index 00ef8d9..9edcf49 100644
--- a/core/modules/user/lib/Drupal/user/Tests/UserPermissionsTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/UserPermissionsTest.php
@@ -17,7 +17,19 @@ class UserPermissionsTest extends WebTestBase {
    * @var \Drupal\user\UserAccess
    */
   protected $accessService;
-  protected $admin_user;
+
+  /**
+   * A user object with administrative permissions.
+   *
+   * @var \Drupal\user\Plugin\Core\Entity\User
+   */
+  protected $adminUser;
+
+  /**
+   * The role ID of an administrative role created per test run.
+   *
+   * @var int
+   */
   protected $rid;
 
   public static function getInfo() {
@@ -31,10 +43,10 @@ public static function getInfo() {
   function setUp() {
     parent::setUp();
     $this->accessService = $this->container->get('user.access');
-    $this->admin_user = $this->drupalCreateUser(array('administer permissions', 'access user profiles', 'administer site configuration', 'administer modules', 'administer users'));
+    $this->adminUser = $this->drupalCreateUser(array('administer permissions', 'access user profiles', 'administer site configuration', 'administer modules', 'administer users'));
 
     // Find the new role ID.
-    $all_rids = $this->admin_user->roles;
+    $all_rids = $this->adminUser->roles;
     unset($all_rids[DRUPAL_AUTHENTICATED_RID]);
     $this->rid = key($all_rids);
   }
@@ -43,9 +55,9 @@ function setUp() {
    * Change user permissions and check \Drupal\user\UserAccess::check().
    */
   function testUserPermissionChanges() {
-    $this->drupalLogin($this->admin_user);
+    $this->drupalLogin($this->adminUser);
     $rid = $this->rid;
-    $account = $this->admin_user;
+    $account = $this->adminUser;
 
     // Add a permission.
     $this->assertFalse($this->accessService->check('administer nodes', $account), 'User does not have "administer nodes" permission.');
@@ -70,7 +82,7 @@ function testUserPermissionChanges() {
    * Test assigning of permissions for the administrator role.
    */
   function testAdministratorRole() {
-    $this->drupalLogin($this->admin_user);
+    $this->drupalLogin($this->adminUser);
     $this->drupalGet('admin/config/people/accounts');
 
     // Set the user's role to be the administrator role.
@@ -85,7 +97,7 @@ function testAdministratorRole() {
     // Aggregator depends on file module, enable that as well.
     $edit['modules[Core][file][enable]'] = TRUE;
     $this->drupalPost('admin/modules', $edit, t('Save configuration'));
-    $this->assertTrue($this->accessService->check('administer news feeds', $this->admin_user), 'The permission was automatically assigned to the administrator role');
+    $this->assertTrue($this->accessService->check('administer news feeds', $this->adminUser), 'The permission was automatically assigned to the administrator role');
   }
 
   /**
@@ -93,7 +105,7 @@ function testAdministratorRole() {
    */
   function testUserRoleChangePermissions() {
     $rid = $this->rid;
-    $account = $this->admin_user;
+    $account = $this->adminUser;
 
     // Verify current permissions.
     $this->assertFalse($this->accessService->check('administer nodes', $account), 'User does not have "administer nodes" permission.');
diff --git a/core/modules/user/lib/Drupal/user/UserAccess.php b/core/modules/user/lib/Drupal/user/UserAccess.php
index 2baf56c..d7000e4 100644
--- a/core/modules/user/lib/Drupal/user/UserAccess.php
+++ b/core/modules/user/lib/Drupal/user/UserAccess.php
@@ -2,15 +2,14 @@
 
 /**
  * @file
- * Contains Drupal\user\UserAccess.
+ * Contains \Drupal\user\UserAccess.
  */
 
 namespace Drupal\user;
 use Drupal\Core\Database\Connection;
 use Symfony\Component\DependencyInjection\ContainerInterface;
-use Drupal\Core\ControllerInterface;
 
-class UserAccess implements ControllerInterface {
+class UserAccess implements UserAccessInterface {
 
   /**
    * A cache of permissions for a user uid.
@@ -46,25 +45,6 @@ public function __construct(Connection $database) {
   /**
    * {@inheritdoc}
    */
-  public static function create(ContainerInterface $container) {
-    return new static($container->get('database'));
-  }
-
-  /**
-   * Determines whether the given user has a given privilege.
-   *
-   * @param $string
-   *   The permission, such as "administer nodes", being checked for.
-   * @param $account
-   *   The account to check.
-   *
-   * @return
-   *   Boolean TRUE if the current user has the requested permission.
-   *
-   * All permission checks in Drupal should go through this function. This
-   * way, we guarantee consistent behavior, and ensure that the superuser
-   * can perform all actions.
-   */
   public function check($string, $account) {
     // User #1 has all privileges:
     if ($account->uid == 1) {
@@ -86,7 +66,7 @@ public function check($string, $account) {
   }
 
   /**
-   * Resets the cache of permissions and roles.
+   * {@inheritdoc}
    */
   public function reset() {
     $this->permissionCache = array();
@@ -94,14 +74,7 @@ public function reset() {
   }
 
   /**
-   * Determines the permissions for one or more roles.
-   *
-   * @param $roles
-   *   An array whose keys are the role IDs of interest, such as $user->roles.
-   *
-   * @return
-   *   An array indexed by role ID. Each value is an array whose keys are the
-   *   permission strings for the given role ID.
+   * {@inheritdoc}
    */
   public function userRolePermissions($roles) {
     $role_permissions = $fetch = array();
@@ -121,7 +94,7 @@ public function userRolePermissions($roles) {
     if ($fetch) {
       // Get from the database permissions that were not in the cache.
       // Only role IDs with at least one permission assigned will return rows.
-      $result = db_query("SELECT rid, permission FROM {role_permission} WHERE rid IN (:fetch)", array(':fetch' => $fetch));
+      $result = $this->database->query("SELECT rid, permission FROM {role_permission} WHERE rid IN (:fetch)", array(':fetch' => $fetch));
 
       foreach ($result as $row) {
         $this->roleCache[$row->rid][$row->permission] = TRUE;
diff --git a/core/modules/user/lib/Drupal/user/UserAccessInterface.php b/core/modules/user/lib/Drupal/user/UserAccessInterface.php
new file mode 100644
index 0000000..7133bb2
--- /dev/null
+++ b/core/modules/user/lib/Drupal/user/UserAccessInterface.php
@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\user\UserAccessInterface.
+ */
+
+namespace Drupal\user;
+
+interface UserAccessInterface {
+
+  /**
+   * Determines whether the given user has a given privilege.
+   *
+   * @param $string
+   *   The permission, such as "administer nodes", being checked for.
+   * @param $account
+   *   The account to check.
+   *
+   * @return
+   *   Boolean TRUE if the account passed has the requested permission.
+   *
+   * All permission checks in Drupal should go through this function. This way,
+   * we guarantee consistent behavior, and ensure that the superuser can perform
+   * all actions.
+   */
+  public function check($string, $account);
+
+  /**
+   * Resets the permissions and roles caches.
+   */
+  public function reset();
+
+  /**
+   * Determines the permissions for one or more roles.
+   *
+   * @param $roles
+   *   An array whose keys are the role IDs of interest, such as $user->roles.
+   *
+   * @return
+   *   An array indexed by role ID. Each value is an array whose keys are the
+   *   permission strings for the given role ID.
+   */
+  public function userRolePermissions($roles);
+
+}