Backporting some stuff from 2.7, that I think must have gotten merged…

… only there by accident

book/security.rst

@@ -817,7 +817,7 @@ You can easily deny access from inside a controller::
         $this->denyAccessUnlessGranted('ROLE_ADMIN', null, 'Unable to access this page!');
 
         // Old way :
-        // if (false === $this->get('security.context')->isGranted('ROLE_ADMIN')) {
+        // if (false === $this->get('security.authorization_checker')->isGranted('ROLE_ADMIN')) {
         //     throw $this->createAccessDeniedException('Unable to access this page!');
         // }
 
@@ -829,6 +829,10 @@ You can easily deny access from inside a controller::
     still now), you could check access directly and throw the ``AccessDeniedException`` as shown
     in the example above).
 
+.. versionadded:: 2.6
+    The ``security.authorization_checker`` service was introduced in Symfony 2.6. Prior
+    to Symfony 2.6, you had to use the ``isGranted()`` method of the ``security.context`` service.
+
 In both cases, a special
 :class:`Symfony\\Component\\Security\\Core\\Exception\\AccessDeniedException`
 is thrown, which ultimately triggers a 403 HTTP response inside Symfony.