code: function _runMocha(reporter, done, waited) {
      if (get('waitForFrameworks') && !waited) {
          var waitFor = (get('waitFor') || whenFrameworksReady).bind(window);
          waitFor(_runMocha.bind(null, reporter, done, true));
          return;
      }
      debug('_runMocha');
      var mocha = window.mocha;
      var Mocha = window.Mocha;
      mocha.reporter(reporter.childReporter(window.location));
      mocha.suite.title = reporter.suiteTitle(window.location);
      mocha.grep(GREP);
      // We can't use `mocha.run` because it bashes over grep, invert, and friends.
      // See https://github.com/visionmedia/mocha/blob/master/support/tail.js#L137
      var runner = Mocha.prototype.run.call(mocha, function (_error) {
          if (document.getElementById('mocha')) {
              Mocha.utils.highlightTags('code');
          }
          done(); // We ignore the Mocha failure count.
      });
      // Mocha's default `onerror` handling strips the stack (to support really old
      // browsers). We upgrade this to get better stacks for async errors.
      //
      // TODO(nevir): Can we expand support to other browsers?
      if (navigator.userAgent.match(/chrome/i)) {
          window.onerror = null;
          window.addEventListener('error', function (event) {
              if (!event.error)
                  return;
              if (event.error.ignore)
                  return;
              runner.uncaught(event.error);
          });
      }
  }
docs: Kicks off a mocha run, waiting for frameworks to load if necessary.
  
  @param {!MultiReporter} reporter Where to send Mocha's events.
  @param {function} done A callback fired, _no error is passed_.