Check that alternate stylesheet load completion did not cause a synchronous style recalc. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS successfullyParsed is true TEST COMPLETE PASS internals.updateStyleAndReturnAffectedElementCount() is not 0 PASS getComputedStyle(document.getElementById('t'), null).color is 'rgb(0, 0, 0)'