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

vendor/symfony/serializer/Encoder/ChainDecoder.php

@@ -0,0 +1,82 @@
+<?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\Serializer\Encoder;
+
+use Symfony\Component\Serializer\Exception\RuntimeException;
+
+/**
+ * Decoder delegating the decoding to a chain of decoders.
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ * @author Lukas Kahwe Smith <smith@pooteeweet.org>
+ */
+class ChainDecoder implements DecoderInterface
+{
+    protected $decoders = array();
+    protected $decoderByFormat = array();
+
+    public function __construct(array $decoders = array())
+    {
+        $this->decoders = $decoders;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    final public function decode($data, $format, array $context = array())
+    {
+        return $this->getDecoder($format)->decode($data, $format, $context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsDecoding($format)
+    {
+        try {
+            $this->getDecoder($format);
+        } catch (RuntimeException $e) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Gets the decoder supporting the format.
+     *
+     * @param string $format
+     *
+     * @return DecoderInterface
+     *
+     * @throws RuntimeException if no decoder is found
+     */
+    private function getDecoder($format)
+    {
+        if (isset($this->decoderByFormat[$format])
+            && isset($this->decoders[$this->decoderByFormat[$format]])
+        ) {
+            return $this->decoders[$this->decoderByFormat[$format]];
+        }
+
+        foreach ($this->decoders as $i => $decoder) {
+            if ($decoder->supportsDecoding($format)) {
+                $this->decoderByFormat[$format] = $i;
+
+                return $decoder;
+            }
+        }
+
+        throw new RuntimeException(sprintf('No decoder found for format "%s".', $format));
+    }
+}