function checkIfAnalyticsLoaded() {
  if (window._gaq && window._gaq._getTracker) {
    // Do tracking with new-style analytics
  } else if (window.urchinTracker) {
    // Do tracking with old-style analytics
  } else {
    // Retry. Probably want to cap the total number of times you call this.
    setTimeout(500, checkIfAnalyticsLoaded());
  }
}

function checkIfAnalyticsLoaded() {
  if (window._gat && window._gat._getTracker) {
    // Do tracking with new-style analytics
  } else if (window.urchinTracker) {
    // Do tracking with old-style analytics
  } else {
    // Probably want to cap the total number of times you call this.
    setTimeout(checkIfAnalyticsLoaded, 500);
  }
}

function check_ga() {
  if (typeof ga === 'function') {
    console.log('Loaded :'+ ga);
  } else {
    console.log('Not loaded');
    setTimeout(check_ga,500);
  }
}
check_ga();

ga(function(tracker) {
  console.log(tracker.get('clientId'));
});

var ga = window[window['GoogleAnalyticsObject'] || 'ga'];
if (typeof ga == 'function') {
  // call ga object here
  ga('send', 'event', 'Social Share Button', 'click', 'facebook');
}

function add(a,b){alert(a + ' + ' + b + ' = ' + (a+b));}
_mygaq(add,1,2);

function _mygaq(fn) {
  this._count = this._count || 0;
  this._running = this._running || false;
  this._q = this._q || [];
  if(arguments.length>0){
    this._q.push({"f":fn,"p":Array.prototype.slice.call(arguments,1)});
  } else {
    this._count++;
  }
  if ((window._gat && window._gat._getTracker) || window.urchinTracker) {
    this._count = 0;
    this._running = false;
    while (this._q.length > 0){
      var _innr = this._q[0];
      this._q = this._q.slice(1);
      _innr.f.apply(_innr.f, _innr.p);
    }
  } else {
    if( (arguments.length==0) || (!this._running && arguments.length>0)){
      if(this._count < 120) setTimeout('_mygaq()', 500);
      this._running = true;
    }
  }
}

let checkIfAnalyticsLoaded = () => {
  return new Promise((resolve, reject) => {
    let timeStart = Date.now();
    const TIMEOUT = 3000;

  let _isLoaded = function() {
    if (Date.now() - timeStart > TIMEOUT) {
      reject('Timeout. Google analytics not injected!');
      return;
    }
    if (window.ga && ga.create) {
      resolve(ga);
      return;
    } else {
      setTimeout(_isLoaded, 500);
    }
  };

  _isLoaded();
  });
}


checkIfAnalyticsLoaded()
  .then((result => {
    console.log('LOADED', result);
  }))
  .catch(console.error);

ga.loaded

var t = setTimeout(function(){
        console.log(ga.loaded);
}, 999);

<script type="text/javascript">
    var counter = 1;
    function checkIfAnalyticsLoaded() {
        if (window.ga) {
            //LOADED!
        } else {
            counter = counter + 1;
            if (counter < 6){
                setTimeout('checkIfAnalyticsLoaded()', 200);
            } else {
                //LOADED!
            }
        }
    }
    window.onload = checkIfAnalyticsLoaded();
    </script>