message: Add a comment to explain the state of affairs for refs.messagePanel
diff: @@ -429,6 +429,12 @@ module.exports = React.createClass({
  roomView.addEventListener('dragend', this.onDragLeaveOrEnd);
  }
  }
  +
  + // Note: We check the ref here with a flag because componentDidMount, despite
  + // documentation, does not define our messagePanel ref. It looks like our spinner
  + // in render() prevents the ref from being set on first mount, so we try and
  + // catch the messagePanel when it does mount. Because we only want the ref once,
  + // we use a boolean flag to avoid duplicate work.
  if (this.refs.messagePanel && !this.state.atEndOfLiveTimelineInit) {
  this.setState({
  atEndOfLiveTimelineInit: true,
  