Edit in JSFiddle

var isBlogspotOk = true;
(function() {
  var img = document.createElement('img');
  img.src = 'https://4.bp.blogspot.com/-S16vb1fTOR4/VGMv1bmlWmI/AAAAAAAAYOM/EXPpU8URM48/s1/';
  if (!img.complete) {
    isBlogspotOk = false;
  }
  if (typeof img.naturalWidth !== 'undefined' && img.naturalWidth === 0) {
    isBlogspotOk = false;
  }
  img.onload = function() {
    isBlogspotOk = true;
    console.log(isBlogspotOk);
  };
  img.onerror = function() {
    isBlogspotOk = false;
    console.log(isBlogspotOk);
  };
}());
console.log(isBlogspotOk);