[Form] added FormBuilderInterface in Tests namespace, so as to enable easy mocking

src/Symfony/Component/Form/Tests/FormBuilderInterface.php

@@ -0,0 +1,16 @@
+<?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\Form\Tests;
+
+interface FormBuilderInterface extends \Iterator, \Symfony\Component\Form\FormBuilderInterface
+{
+}