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

vendor/symfony/validator/Context/LegacyExecutionContext.php

@@ -0,0 +1,55 @@
+<?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\Validator\Context;
+
+@trigger_error('The '.__NAMESPACE__.'\LegacyExecutionContext class is deprecated since version 2.5 and will be removed in 3.0.', E_USER_DEPRECATED);
+
+use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Component\Validator\MetadataFactoryInterface;
+use Symfony\Component\Validator\Validator\ValidatorInterface;
+
+/**
+ * An execution context that is compatible with the legacy API (< 2.5).
+ *
+ * @since  2.5
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ *
+ * @deprecated since version 2.5, to be removed in 3.0.
+ */
+class LegacyExecutionContext extends ExecutionContext
+{
+    /**
+     * @var MetadataFactoryInterface
+     */
+    private $metadataFactory;
+
+    /**
+     * Creates a new context.
+     *
+     * @see ExecutionContext::__construct()
+     *
+     * @internal Called by {@link LegacyExecutionContextFactory}. Should not be used
+     *           in user code.
+     */
+    public function __construct(ValidatorInterface $validator, $root, MetadataFactoryInterface $metadataFactory, TranslatorInterface $translator, $translationDomain = null)
+    {
+        parent::__construct(
+            $validator,
+            $root,
+            $translator,
+            $translationDomain
+        );
+
+        $this->metadataFactory = $metadataFactory;
+    }
+}