Performance bookmarklet for Angularjs

angular-performance.js

var bindings = document.getElementsByClassName('ng-binding').length;
var scopes = document.getElementsByClassName('ng-scope').length;

var bodyScope = angular.element(document.querySelector('body')).scope();
var watchers = bodyScope && bodyScope.$$watchers ? bodyScope.$$watchers.length : '?';

var getWatchers = function () { 
    var root = document.getElementsByTagName('body')[0];
    var numberOfWatches = 0;

    var f = function (element) {
      var $element = angular.element(element);
      var watchers = $element.scope().$$watchers;
      if(watchers){
        numberOfWatches += watchers.length;
      }

      angular.forEach($element.children(), function (childElement) {
          f(childElement);
      });
    };

    f(root);

    return numberOfWatches;
};

console.log('Bindings: ', bindings);
console.log('Scopes: ', scopes);
console.log('Watchers (Body): ', watchers);
//console.log('Watchers (Entire page): ', getWatchers());