Fullsize background videos in webkit browsers gist 6

gistfile1.js

// quick and dirty check for webkit, which has a bug that it does not compute the
// proper scrollTop, when overflowX is set on the body. We can use this to decide
// when we have to disable fixed-attachment backgrounds, because they lead to a rendering
// issue in webkit. This test is just a naive implementation and probably could be improved
// but works fine for now.
var overflowScrollTopBuggy = function overflowScrollTopBuggy () {
    if (testFixedBackgrounds.buggy) {
        return testFixedBackgrounds.buggy;
    }
    var body = document.querySelector('body');
    var s = document.createElement('style');
    s.innerHTML = 'html,body {overflow-x: hidden;}';
    body.appendChild(s);
    body.scrollTop = 1;
    overflowScrollTopBuggy.buggy = (body.scrollTop === 0);
    body.scrollTop = 0;
    body.removeChild(s);
    return overflowScrollTopBuggy.buggy;
};