let scrolled;
let div = this.template.querySelector(".resultsscroll");

div.onscroll = function() {
    scrolled = true;
}

let scrollIntervalId = setInterval(() => {
    if (scrolled) {
        scrolled = false;

        if (this.aThingINeed && div.scrollHeight - div.scrollTop < 300) {
            // do stuff
        }
    }
}, 750);

this.scrollIntervalId = scrollIntervalId;

afterRender : function(component, helper, event) {
    this.superAfterRender();

    let scrolled;
    let div = component.find('resultsscroll');
    if (!$A.util.isEmpty(div)) {
        div = div.getElement();
        div.onscroll = () => scrolled = true;

        let scrollIntervalId = setInterval($A.getCallback(() => {
            if (scrolled) {
                scrolled = false;

                if (component.get("v.aThingINeed") && div.scrollHeight - div.scrollTop < 300) {
                    // do stuff
                }
            }
        }), 750);

        component.set('v.scrollIntervalId', scrollIntervalId);
    }
},

unrender: function( component, helper ) {
    this.superUnrender();

    window.clearInterval(component.get("v.scrollIntervalId"));
}