There's no reason that we only actually find references for reftests on the Worker itself. By the time we reach the Worker, we really should know exactly what we're going to run. Ideally, we'd be finding the references long before this, but for now let's move it to the LayoutTestFinder.
Created attachment 419634 [details] Patch
Created attachment 419639 [details] Patch
Created attachment 419643 [details] Patch
Committed r272568: <https://commits.webkit.org/r272568> All reviewed patches have been landed. Closing bug and clearing flags on attachment 419643 [details].
<rdar://problem/74206576>