Convert simpletest tests to use ::$modules property instead of parent::setUp($modules)

+++ b/core/modules/simpletest/lib/Drupal/simpletest/Tests/SimpleTestTest.php
@@ -32,14 +40,14 @@ class SimpleTestTest extends WebTestBase {
-      parent::setUp('non_existent_module');
+      $this::$modules = array('non_existent_module');

This is the only change I'm uncertain of. Instead of $this::$modules, would self::$modules be a better choice? I'm kind of a OO noob so I wouldn't know better, but my reasoning lies in example #2 at http://www.php.net/manual/en/language.oop5.paamayim-nekudotayim.php

class OtherClass extends MyClass
{
    public static $my_static = 'static var';

    public static function doubleColon() {
        echo parent::CONST_VALUE . "\n";
        echo self::$my_static . "\n";
    }
}

and from http://stackoverflow.com/a/151976/1097146

Use $this to refer to the current object. Use self to refer to the current class. In other words, use $this->member for non-static members, use self::$member for static members.

Since in this case we're altering the class definition instead of an instantiation, I think self:: may be better?

Sorry, I'm not sure if this needs work or not, it definitely needs more review than my two noob cents :)

@tim.plunket

I think you had a typo there. Instead of $self::$modules, it should be self::$modules.

I created a patch that uses self::$modules instead and it passed for me locally.