Drag & drop doesn't work on mobile Chrome when zoomed in

[tsim0]

After doing some debugging, it seems like the problem is in using $.offset to get elements offset which works incorrectly on Chrome. https://bugs.jquery.com/ticket/5565
Something like monkey patching $.offset like this solves the issue.

$.prototype.offset = function() {
  return {
    left: this[0].offsetLeft,
    top: this[0].offsetTop
  };
};