[galaxy-user] display at UCSC main (gbrowse)

When a data is in BED format or Customtrack and build is on of ucsc, a link shows up with a link to "display at UCSC main". I was wondering if this would be possible to do with gbrowse for data in Gff or Gff3. I added gbrowse links to: tool-data/shared/gbrowse/gbrowse_build_sites.txt for data in gff format, lib/galaxy/datatypes/interval.py has add_display_app in it, but I was not able to get a link on my dataset. What exactly do I have to do to get a link to "display in Gbrowse"? thanks! rochak