Paste it to developer console and click on any element.

Debugging event bubbling

var eventsToBeDebuggedSeperatedBySpaces = 'focus';
$('*').each(function(){
      var eventHandler = function(event) {
        var el = $(event.currentTarget).clone();
        var str = $("<div>").append(el).html();
        str = str.substring(0, str.indexOf(el.html()))
        console.log(str.trim().length == 0 ? this.tagName : str.substr(0, 120));
      }.bind(this);
      this.addEventListener(eventsToBeDebuggedSeperatedBySpaces, eventHandler, true);
      this.addEventListener(eventsToBeDebuggedSeperatedBySpaces, eventHandler, false);
  });