How do I enable modules in a Simpletest-Selenium test (Selenium module)?
It should work completely the same. You should be able to enable modules passing arguments to setUp().

Implementation of the setUp() method for DrupalSeleniumWebTestCase is

protected function setUp() {
  $modules = func_get_args();
  parent::setUp($modules);
  //...
}


So everything passed to it is passed to parent setUp method that should enable modules for you.