hiftTabPressed = true;
      this.setAttribute('tabindex', '-1');
      this.async(function() {
        this.setAttribute('tabindex', oldTabIndex);
        this._shiftTabPressed = false;
      }, 1);
    },

    /**
     * If `autoValidate` is true, then validates the element.
     */
    _handleAutoValidate: function() {
      if (this.autoValidate)
        this.validate();
    },

    /**
     * Restores the cursor to its original position after updating the value.
     * @param {string} newValue The valu