WorkerGlobalScope worker set does not appear to be used

[domfarolino]

The title says it all: https://html.spec.whatwg.org/multipage/workers.html#the-worker's-workers is written to upon sub-worker creation, but never seems to be referenced elsewhere. Is it subtly needed in ways I'm not seeing?

[annevk]

I suspect I modeled it after "the worker's workers", see 59a4750. It looks like that was only there to populate the owner set (formerly the worker's Documents) though so I suspect it can be removed.

(I have vague concerns that we don't deal with lifetime and ownership well. E.g., what holds a Worker or SharedWorker object alive if all it has are event listeners? But this doesn't really address that nor would it be the right solution I think.)

[domenic]

Agreed, it'd be nice to remove this. "owner set" is the thing that specs use.