Function indexOf

06.Router/basic/js/vue.js:353–359

* Manual indexOf because it's slightly faster than * native. * * @param {Array} arr * @param {*} obj

(arr, obj)

   */

  function indexOf(arr, obj) {
    var i = arr.length;
    while (i--) {
      if (arr[i] === obj) return i;
    }
    return -1;
  }

  /**
   * Make a cancellable version of an async callback.