<!DOCTYPE html> <html class="reftest-wait"> <head> <script> var expectedLoads = 3; function load_done() { --expectedLoads; if (expectedLoads == 0) { document.documentElement.className = ""; } } function addLink() { var l = document.createElement("link"); l.rel = "stylesheet"; l.type = "text/css"; l.href = "data:text/css,some { random: data }"; l.onload = load_done; document.getElementsByTagName("head")[0].appendChild(l); } function doIt() { document.styleSheets[0].insertRule('a {}', 0) addLink(); addLink(); } addLink(); </script> </head> <body onload="doIt()"> <body> </body>