Helen,
OK so I found the difference between your data and mine that I was testing. Mine was using wkid 102100 like the maps wkid.
So make this change (line 6):
var qt = QueryTask(layerInfo.getUrl());
var q = Query();
q.returnGeometry = true;
q.where = layerFilterExpr;
q.outSpatialReference = this.map.spatialReference;
qt.execute(q, lang.hitch(this, function(fs){
this.map.setExtent(graphicsUtils.graphicsExtent(fs.features), true);
}));