open new window after click but determined by ajax result

a.html

<button class="btn">123</button>

a.js

$('.btn').on("click", function(){
    var ajax = new $.Deferred();
    $.ajax({
        url: '/',
        success: function (data) {
            if (data) {
                ajax.resolve();
            }
        }
    });
    openNewWin('http://www.baidu.com', ajax);
});

function openNewWin(url, ajax, waiting) {
    var stack = [], current = 0;
    waiting = waiting > 0 ? waiting : 5;
    for (var i = 1; i < waiting; i++ ) {
       stack.push(setTimeout(function() {
           if (ajax.state() == "resolved") {
               $.each(stack, function (key, val) {
                   console.log(val);
                   clearTimeout(val);
               });
               window.open(url);
           } else {
               stack.shift();
           }
       }, i * 1000))
    }
}