This would include all of Bar's signatures into Foo, and then Foo would be a subprotocol of Bar.
Created attachment 320519 [details] the patch
Comment on attachment 320519 [details] the patch Looks good.
Landed in https://trac.webkit.org/changeset/221940/webkit
<rdar://problem/34693720>
Migrated to https://github.com/gpuweb/WHLSL/issues/197