From http://joshbroton.com/hooking-up-to-the-window-onscroll-event-without-killing-your-performance/

onScrollEvent

var didScroll = false;

window.onscroll = doThisStuffOnScroll;

function doThisStuffOnScroll() {
    didScroll = true;
}

setInterval(function() {
    if(didScroll) {
        didScroll = false;
        console.log('You scrolled');
    }
}, 100);