javascript event: get when document is textually fully loaded but scripts haven't ran yet

javascript event: get when document is textually fully loaded but scripts
haven't ran yet

DOMContentLoaded fires after document is loaded and its scripts ran, and
I'd like to run my code before scripts were executed but after
document.body.outerHTML (
document.childNodes[document.childNodes.length-1].outerHTML ) is full
I try this, but looks like it runs many times after is found also so now I
do a timer 200ms job before executing mycode, but i'd like to do it
without timers
var observer = new MutationObserver(function(mutations)
{
if(document.body &&
document.childNodes[document.childNodes.length-1].outerHTML.lastIndexOf("</html>")!=-1)
{
observer.disconnect();
mycode();
}
});
observer.observe(document, {subtree: true, childList: true});
Needs to work in Chrome (so beforescriptexecuted event won't work here)