Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/lib/Drupal/Component/Serialization/PhpSerialize.php

@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Component\Serialization\PhpSerialize.
+ */
+
+namespace Drupal\Component\Serialization;
+
+/**
+ * Default serialization for serialized PHP.
+ */
+class PhpSerialize implements SerializationInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function encode($data) {
+    return serialize($data);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function decode($raw) {
+    return unserialize($raw);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getFileExtension() {
+    return 'serialized';
+  }
+
+}