Some string parameters default to "undefined", however the code path is the same when no default is given and implicitly a null string is passed, so remove the default values.
Created attachment 408601 [details] Patch
Created attachment 408646 [details] Patch
Committed r267000: <https://trac.webkit.org/changeset/267000> All reviewed patches have been landed. Closing bug and clearing flags on attachment 408646 [details].
<rdar://problem/68809745>