is._handleValueAndAutoValidate(event.target);
    },

    _onValueChanged: function(event) {
      this._handleValueAndAutoValidate(event.target);
    },

    _handleValue: function(inputElement) {
      var value = this._inputElementValue;

      // type="number" hack needed because this.value is empty until it's valid
      if (value || value === 0 || (inputElement.type === 'number' && !inputElement.checkValidity())) {
        this._inputHasContent = true;
      } else {
        this._inputHasContent = fa