The Mac port waits until the first input comes from some gamepad before calling GamepadProvider::setShouldMakeGamepadsVisible(), and it would be a good idea to do the same for the GTK port.
Created attachment 411049 [details] Patch
Committed r268390: <https://trac.webkit.org/changeset/268390> All reviewed patches have been landed. Closing bug and clearing flags on attachment 411049 [details].