diff -u b/core/modules/system/lib/Drupal/system/Tests/PhpLoader/MTimeProtectedLoaderTest.php b/core/modules/system/lib/Drupal/system/Tests/PhpLoader/MTimeProtectedLoaderTest.php
--- b/core/modules/system/lib/Drupal/system/Tests/PhpLoader/MTimeProtectedLoaderTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/PhpLoader/MTimeProtectedLoaderTest.php
@@ -7,16 +7,14 @@
 
 namespace Drupal\system\Tests\PhpLoader;
 
-use Drupal\simpletest\UnitTestBase;
-
 /**
  * Tests the directory mtime based PHP loader implementation.
  */
-class MTimeProtectedLoaderTest extends UnitTestBase {
+class MTimeProtectedLoaderTest extends PhpLoaderTestBase {
 
   public static function getInfo() {
     return array(
-      'name' => 'Loader test',
+      'name' => 'MTime loader',
       'description' => 'Tests the protected loader.',
       'group' => 'System',
     );
@@ -31,21 +29,11 @@
    */
   public function testMTimeProtectedLoader() {
-    $conf['loader_classes'] = array('default' =>
+    $this->doTest(array('default' =>
       array(
         'class' => 'Drupal\Component\PhpLoader\MTimeProtectedLoader',
         'prefix' => variable_get('file_public_path', conf_path() . '/files') . '/codegen',
         'secret' => $GLOBALS['drupal_hash_salt'],
       ),
-    );
-    drupal_static_reset('_drupal_php_get_loader');
-    $filename = $this->randomName() . '/' . $this->randomName() . '.php';
-    do {
-      $random = mt_rand(10000, 100000);
-      $function = 'test' . $random;
-    } while (function_exists($function));
-    $contents = "<?php\nfunction $function() { return $random;}";
-    drupal_php_loader()->write($filename, $contents);
-    drupal_php_loader()->includePhp($filename);
-    $this->assertIdentical($function(), $random);
+    ));
   }
 }
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/system/lib/Drupal/system/Tests/PhpLoader/NativeLoaderTest.php
@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\system\Tests\PhpLoader\MTimeProtectedLoaderTest
+ */
+
+namespace Drupal\system\Tests\PhpLoader;
+
+/**
+ * Tests the native loader.
+ */
+class NativeLoaderTest extends PhpLoaderTestBase {
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Native loader',
+      'description' => 'Tests the native loader.',
+      'group' => 'System',
+    );
+  }
+
+  /**
+   * Tests the directory mtime based PHP loader implementation.
+   *
+   * This test first writes a file containing the definition of a non-existing
+   * function returning a random. Then loads it back, calls the function and
+   * asserts the return is correct.
+   */
+  public function testNativeLoader() {
+    $this->doTest(array('default' =>
+      array(
+        'class' => 'Drupal\Component\PhpLoader\NativeLoader',
+        'prefix' => variable_get('file_public_path', conf_path() . '/files') . '/codegen',
+      ),
+    ));
+  }
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/system/lib/Drupal/system/Tests/PhpLoader/PhpLoaderTestBase.php
@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\system\Tests\PhpLoader\PhpLoaderTestBase.
+ */
+
+namespace Drupal\system\Tests\PhpLoader;
+
+use Drupal\simpletest\UnitTestBase;
+
+/**
+ * Base test for PHP loaders.
+ */
+abstract class PhpLoaderTestBase extends UnitTestBase {
+
+  /**
+   * Test a loader.
+   *
+   * @param array $loader
+   *   A loader configuration array as used for the loader_classes variable in
+   *   drupal_php_loader().
+   */
+  public function doTest($loader) {
+    $conf['loader_classes'] = $loader;
+    drupal_static_reset('_drupal_php_get_loader');
+    $filename = $this->randomName() . '/' . $this->randomName() . '.php';
+    do {
+      $random = mt_rand(10000, 100000);
+      $function = 'test' . $random;
+    } while (function_exists($function));
+    $contents = "<?php\nfunction $function() { return $random;}";
+    drupal_php_loader()->write($filename, $contents);
+    drupal_php_loader()->includePhp($filename);
+    $this->assertIdentical($function(), $random);
+  }
+}