code: function makeOpenTabItem(tab) {
    var urlStr = tab.url;
    if (!urlStr) {
      console.error('malformed tab -- no URL: ', tab);
      urlStr = '';
    }
    /*
      if (!tab.title) {
        console.warn("tab missing title (ignoring...): ", tab);
      }
    */
    var tabItem = new TabItem({
      url: urlStr,
      audible: tab.audible,
      favIconUrl: tab.favIconUrl,
      open: true,
      tabTitle: _.get(tab, 'title', urlStr),
      openTabId: tab.id,
      active: tab.active,
      openTabIndex: tab.index
    });
    return tabItem;
  }
docs: Initialize a TabItem from an open Chrome tab