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

vendor/symfony/http-kernel/DataCollector/EventDataCollector.php

@@ -0,0 +1,107 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel\DataCollector;
+
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\EventDispatcher\Debug\TraceableEventDispatcherInterface;
+
+/**
+ * EventDataCollector.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class EventDataCollector extends DataCollector implements LateDataCollectorInterface
+{
+    protected $dispatcher;
+
+    public function __construct(EventDispatcherInterface $dispatcher = null)
+    {
+        $this->dispatcher = $dispatcher;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function collect(Request $request, Response $response, \Exception $exception = null)
+    {
+        $this->data = array(
+            'called_listeners' => array(),
+            'not_called_listeners' => array(),
+        );
+    }
+
+    public function lateCollect()
+    {
+        if ($this->dispatcher instanceof TraceableEventDispatcherInterface) {
+            $this->setCalledListeners($this->dispatcher->getCalledListeners());
+            $this->setNotCalledListeners($this->dispatcher->getNotCalledListeners());
+        }
+    }
+
+    /**
+     * Sets the called listeners.
+     *
+     * @param array $listeners An array of called listeners
+     *
+     * @see TraceableEventDispatcherInterface
+     */
+    public function setCalledListeners(array $listeners)
+    {
+        $this->data['called_listeners'] = $listeners;
+    }
+
+    /**
+     * Gets the called listeners.
+     *
+     * @return array An array of called listeners
+     *
+     * @see TraceableEventDispatcherInterface
+     */
+    public function getCalledListeners()
+    {
+        return $this->data['called_listeners'];
+    }
+
+    /**
+     * Sets the not called listeners.
+     *
+     * @param array $listeners An array of not called listeners
+     *
+     * @see TraceableEventDispatcherInterface
+     */
+    public function setNotCalledListeners(array $listeners)
+    {
+        $this->data['not_called_listeners'] = $listeners;
+    }
+
+    /**
+     * Gets the not called listeners.
+     *
+     * @return array An array of not called listeners
+     *
+     * @see TraceableEventDispatcherInterface
+     */
+    public function getNotCalledListeners()
+    {
+        return $this->data['not_called_listeners'];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getName()
+    {
+        return 'events';
+    }
+}