defaultAlternateFormControlDesignEnabled() can't read UIUserInterfaceIdiom in the Web Content process
Created attachment 440584 [details] Patch
<rdar://problem/84009054>
Created attachment 440585 [details] Patch
Committed r283813 (242705@main): <https://commits.webkit.org/242705@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 440585 [details].