WKPageIsPlayingVideoInEnhancedFullscreen is declared for macOS and iOS, but it is only implemented for macOS.
The reason is that TARGET_OS_MAC is true for both.
Created attachment 302898 [details]
Comment on attachment 302898 [details]
Clearing flags on attachment: 302898
Committed r213112: <http://trac.webkit.org/changeset/213112>
All reviewed patches have been landed. Closing bug.