REGRESSION (iOS 16.4): Form controls are drawn incorrectly when lockdown mode is enabled

[pxlcoder]

ca4bed3

REGRESSION (iOS 16.4): Form controls are drawn incorrectly when lockdown mode is enabled
https://bugs.webkit.org/show_bug.cgi?id=254719
rdar://104829495

Reviewed by Wenson Hsieh and Brent Fulgham.

Form controls on iOS were redesigned in iOS 15. To aid with testing and debugging
the `IOSFormControlRefreshEnabled` feature flag was introduced. This flag was
enabled by default in iOS 15.

However, 258448@main miscategorized the feature as "unstable", and as of 257758@main,
all "unstable" features are disabled in lockdown mode. This feature should not
be disabled in any shipping configuration.

* Source/WTF/Scripts/Preferences/UnifiedWebPreferences.yaml:

Mark the feature as "internal", since it is only intended for debugging purposes,
is not web API, and has shipped in a much older release.

The flag can likely be removed entirely now, however, that is a much larger change
involving a great deal of code removal across many files.

Canonical link: https://commits.webkit.org/262338@main

cd490f1

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
✅ 🛠 🧪 jsc	✅ 🛠 tv	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
✅ 🛠 🧪 jsc-arm64	✅ 🛠 tv-sim	✅ 🧪 mac-AS-debug-wk2	✅ 🛠 jsc-armv7
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress	✅ 🧪 jsc-armv7-tests
	✅ 🛠 watch-sim		✅ 🛠 jsc-mips
✅ 🛠 🧪 unsafe-merge			✅ 🧪 jsc-mips-tests

[webkit-early-warning-system]

EWS run on current version of this PR (hash cd490f1)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
✅ 🛠 🧪 jsc	✅ 🛠 tv	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
✅ 🛠 🧪 jsc-arm64	✅ 🛠 tv-sim	✅ 🧪 mac-AS-debug-wk2	✅ 🛠 jsc-armv7
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress	✅ 🧪 jsc-armv7-tests
	✅ 🛠 watch-sim		✅ 🛠 jsc-mips
✅ 🛠 🧪 unsafe-merge			✅ 🧪 jsc-mips-tests

[webkit-commit-queue]

Committed 262338@main (ca4bed3): https://commits.webkit.org/262338@main

Reviewed commits have been landed. Closing PR #12158 and removing active labels.