Merge branch '4.0'

* 4.0:
  Revert "bug #25151 [FrameworkBundle] Automatically enable the CSRF protection if CSRF manager exists (sroze)"
  Revert "bug #25502 Fixing wrong class_exists on interface (weaverryan)"

Author: fabpot

DependencyInjection/Configuration.php

@@ -21,7 +21,6 @@
 use Symfony\Component\Form\Form;
 use Symfony\Component\Lock\Lock;
 use Symfony\Component\Lock\Store\SemaphoreStore;
-use Symfony\Component\Security\Csrf\CsrfTokenManagerInterface;
 use Symfony\Component\Serializer\Serializer;
 use Symfony\Component\Translation\Translator;
 use Symfony\Component\Validator\Validation;
@@ -110,7 +109,7 @@ private function addCsrfSection(ArrayNodeDefinition $rootNode)
         $rootNode
             ->children()
                 ->arrayNode('csrf_protection')
-                    ->{!class_exists(FullStack::class) && interface_exists(CsrfTokenManagerInterface::class) ? 'canBeDisabled' : 'canBeEnabled'}()
+                    ->canBeEnabled()
                 ->end()
             ->end()
         ;