[Security] Add PHPDoc to AuthenticationEvents

src/Symfony/Component/Security/Core/AuthenticationEvents.php

@@ -13,7 +13,26 @@ namespace Symfony\Component\Security\Core;
 
 final class AuthenticationEvents
 {
+    /**
+     * The AUTHENTICATION_SUCCESS event occurs after a user is authenticated
+     * by one provider.
+     *
+     * The event listener method receives a
+     * Symfony\Component\Security\Core\Event\AuthenticationEvent instance.
+     *
+     * @var string
+     */
     const AUTHENTICATION_SUCCESS = 'security.authentication.success';
 
+    /**
+     * The AUTHENTICATION_FAILURE event occurs after a user cannot be
+     * authenticated by any of the providers.
+     *
+     * The event listener method receives a
+     * Symfony\Component\Security\Core\Event\AuthenticationFailureEvent
+     * instance.
+     *
+     * @var string
+     */
     const AUTHENTICATION_FAILURE = 'security.authentication.failure';
 }