gistfile1.js

var unfav = document.getElementsByClassName('with-icn unfavorite js-tooltip')[0]; 
var fav = document.getElementsByClassName('with-icn favorite js-tooltip')[0]; 
var count = 0;
var max_count = 100;
var timInterval = setInterval(function () {
  fav.click();
  setTimeout(function () {
    unfav.click();
    count++;
    if (count == max_count) clearInterval(timInterval);
  }, 1000);
}, 2500);