Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/symfony-cmf/routing/Event/Events.php

@@ -0,0 +1,29 @@
+<?php
+
+/*
+ * This file is part of the Symfony CMF package.
+ *
+ * (c) 2011-2014 Symfony CMF
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Cmf\Component\Routing\Event;
+
+final class Events
+{
+    /**
+     * Fired before a path is matched in \Symfony\Cmf\Component\Routing\DynamicRouter#match
+     *
+     * The event object is RouteMatchEvent.
+     */
+    const PRE_DYNAMIC_MATCH = 'cmf_routing.pre_dynamic_match';
+
+    /**
+     * Fired before a Request is matched in \Symfony\Cmf\Component\Routing\DynamicRouter#match
+     *
+     * The event object is RouteMatchEvent.
+     */
+    const PRE_DYNAMIC_MATCH_REQUEST = 'cmf_routing.pre_dynamic_match_request';
+}