Merge branch '3.0'

* 3.0:
  [3.0] [Tests] minor fix following #17787
  [2.8] [Form] minor fix some tests with placeholder in AbstractLayout
  [DependencyInjection] fix tests
  Validate XLIFF translation files
  [DependencyInjection] replace alias in factories
  replace alias in factory services

Tests/Resources/TranslationFilesTest.php

@@ -0,0 +1,31 @@
+<?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\Tests\Resources;
+
+class TranslationFilesTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @dataProvider provideTranslationFiles
+     */
+    public function testTranslationFileIsValid($filePath)
+    {
+        \PHPUnit_Util_XML::loadfile($filePath, false, false, true);
+    }
+
+    public function provideTranslationFiles()
+    {
+        return array_map(
+            function ($filePath) { return (array) $filePath; },
+            glob(dirname(dirname(__DIR__)).'/Resources/translations/*.xlf')
+        );
+    }
+}