I'll be adding `ENABLE_PDF_PLUGIN` which will be true on iOS too.
<rdar://problem/116538277>
Pull request: https://github.com/WebKit/WebKit/pull/18714
Committed 268960@main (6dc509259724): <https://commits.webkit.org/268960@main> Reviewed commits have been landed. Closing PR #18714 and removing active labels.