selectByAsset(asset) {
    this.card_.classList.remove('selected');
    if (this.asset_ == asset) {
      this.card_.classList.add('selected');
    }
  }
Select this card if the card's asset matches |asset|.
Used to simplify the implementation of "shaka-main-selected-asset-changed"
handlers.
@param {ShakaDemoAssetInfo} asset