function loadImage(attrs, fn){
  fn = fn || function(){};
  var img = new Image();
  img.onerror = error(fn, 'failed to load pixel', img);
  img.onload = function(){ fn(); };
  img.src = attrs.src;
  img.width = 1;
  img.height = 1;
  return img;
}
TODO: Document me

@api private
@param {Object} attrs
@param {Function} fn
@return {undefined}