<!DOCTYPE html> <html class="reftest-wait"> <iframe id="x" src="data:text/html;charset=utf-8,%3Cdiv%20id%3D%22a%22%3Eaaa"></iframe> <script> window.onload = function() { window.frames[0].document.getElementById("a").setAttribute("style", '-moz-transition-property: color;' + '-moz-transition-duration: 10s;' + 'transition-property: color;' + 'transition-duration: 10s; ' + 'color: red;'); // And start the transition window.frames[0].document.documentElement.getBoundingClientRect(); // Now kill off the presshell var frame = document.getElementById("x"); frame.style.display = "none"; document.documentElement.getBoundingClientRect(); // And wait for the refresh driver to fire setTimeout(function() { document.documentElement.className = ""; }, 100); } </script> </html>