<!DOCTYPE html> <script> if (window.testRunner) testRunner.dumpAsText(); onload = function() { var iframe = document.createElement('iframe'); document.getElementById("div").appendChild(iframe); var iframeDoc = iframe.contentWindow.document; var style = iframeDoc.createProcessingInstruction('xml-stylesheet', 'href="null.css" type="text/css"'); iframeDoc.insertBefore(style, iframeDoc.firstChild); style.deleteData(0, 0); style.deleteData(10, 1); } </script> <div id="div">PASS</div>