<!DOCTYPE HTML> <html class="reftest-wait"> <head> <style> div { width: 200px; height: 200px; } #one { background-color: green; visibility: hidden; } #two { background-color: red; } #three { position: absolute; width: 500px; height: 500px; top: 0px; background-color: rgba(0,0,255,0.2); } </style> </head> <body> <div id="one"></div> <div id="two"></div> <div id="three"></div> <script> function doTest2() { document.getElementById("three").style.backgroundColor = "rgba(255,0,255,0.2)"; document.documentElement.removeAttribute('class'); } function doTest() { document.getElementById("one").style.visibility = "visible"; window.requestAnimationFrame(function() { window.requestAnimationFrame(doTest2); }); } window.addEventListener("MozReftestInvalidate", doTest); </script> </body> </html>