B2G/gecko/browser/components/tabview/groupitems.js
//    closedLastTab - boolean indicates the last tab has just been closed
boolean indicates the last tab has just been closed
boolean indicates the last tab has just been closed
function GroupItem_newTab(url, options) {
    if (options && options.closedLastTab)
      UI.closedLastTabInTabView = true;
    UI.setActive(this, { dontSetActiveTabInGroup: true });
    let dontZoomIn = !!(options && options.dontZoomIn);
    return gBrowser.loadOneTab(url || gWindow.BROWSER_NEW_TAB_URL, { inBackground: dontZoomIn });
  }
function GroupItem_newTab ( url , options ) { if ( options && options . closedLastTab ) UI . closedLastTabInTabView = true ; UI . setActive ( this , { dontSetActiveTabInGroup : true } ) ; let dontZoomIn = ! ! ( options && options . dontZoomIn ) ; return gBrowser . loadOneTab ( url || gWindow . BROWSER_NEW_TAB_URL , { inBackground : dontZoomIn } ) ; }
closedLastTab - boolean indicates the last tab has just been closed
closedLastTab - boolean indicates the last tab has just been closed