Convert _file_test_form to the new form interface and convert route.

Tagging.

Patch applies cleanly.

File uploading tests pass successfully after applying.

I have also had a look at the code of the patch and looks OK to me.

+++ b/core/modules/file/tests/file_test/file_test.moduleundefined
@@ -19,9 +19,7 @@
 function file_test_menu() {
   $items['file-test/upload'] = array(
     'title' => 'Upload test',
-    'page callback' => 'drupal_get_form',
-    'page arguments' => array('_file_test_form'),
-    'access arguments' => array('access content'),
+    'route_name' => 'file_test',
     'type' => MENU_CALLBACK,
   );
   return $items;

Since this is a MENU_CALLBACK I think we can get rid of the entire file_test_menu function.

Removed file_test_menu().

File upload tests still pass.

That's fine now.

Committed eb354a5 and pushed to 8.x. Thanks!