componentDidUpdate() {
      const { mediaPaths, value, onRemoveInsertedMedia, onChange } = this.props;
      const mediaPath = mediaPaths.get(this.controlID);
      if (mediaPath && mediaPath !== value) {
        onChange(mediaPath);
      } else if (mediaPath && mediaPath === value) {
        onRemoveInsertedMedia(this.controlID);
      }
    }
If there is a media path for this control in the state object, and that
path is different than the value in `nextProps`, update.