message: FixedLayout: supported getRootRef property
diff: @@ -17,6 +17,7 @@ export default class FixedLayout extends React.Component {
  children: PropTypes.node,
  style: PropTypes.object,
  className: PropTypes.string,
  + getRootRef: PropTypes.func,
  vertical: PropTypes.oneOf(['top', 'bottom'])
  };
  @@ -58,10 +59,15 @@ export default class FixedLayout extends React.Component {
  });
  };
  - getRef = el => this.el = el;
  + getRef = el => {
  + if (this.props.getRootRef) {
  + this.props.getRootRef(el);
  + }
  + this.el = el;
  + };
  render () {
  - const { className, children, style, vertical, ...restProps } = this.props;
  + const { className, children, style, vertical, getRootRef, ...restProps } = this.props;
  const tabbarPadding = this.context.hasTabbar ? tabbarHeight : 0;
  const paddingBottom = vertical === 'bottom' && this.context.insets && this.context.insets.bottom
  ? this.context.insets.bottom + tabbarPadding
  