in Documents/assets/smoothscroll/smooth-scroll.js [615:626]
function isInsideYoutubeVideo(event) {
var elem = event.target;
var isControl = false;
if (document.URL.indexOf ('www.youtube.com/watch') != -1) {
do {
isControl = (elem.classList &&
elem.classList.contains('html5-video-controls'));
if (isControl) break;
} while (elem = elem.parentNode);
}
return isControl;
}