Reduce unsafeness in MathMLRowElement

[annevk]

b43f2f0

Reduce unsafeness in MathMLRowElement
https://bugs.webkit.org/show_bug.cgi?id=304672

Reviewed by Rob Buis.

Apply https://github.com/WebKit/WebKit/wiki/Safer-CPP-Guidelines and
address a couple of minor nits in surrounding code.

Canonical link: https://commits.webkit.org/304933@main

f393730

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows	Apple Internal
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win	✅ 🛠 ios-apple
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	🧪 win-tests	✅ 🛠 mac-apple
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe		✅ 🛠 vision-apple
	✅ 🧪 ios-wk2-wpt	✅ 🧪 api-mac-debug	✅ 🛠 wpe-cairo-libwebrtc
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 api-gtk
	✅ 🧪 vision-wk2	✅ 🧪 mac-wk2-stress	✅ 🛠 playstation
✅ 🛠 🧪 unsafe-merge	✅ 🛠 tv	✅ 🧪 mac-intel-wk2
	✅ 🛠 tv-sim	✅ 🛠 mac-safer-cpp
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash f393730)

Details

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows	Apple Internal
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win	✅ 🛠 ios-apple
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	🧪 win-tests	✅ 🛠 mac-apple
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe		✅ 🛠 vision-apple
	✅ 🧪 ios-wk2-wpt	✅ 🧪 api-mac-debug	✅ 🛠 wpe-cairo-libwebrtc
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 api-gtk
	✅ 🧪 vision-wk2	✅ 🧪 mac-wk2-stress	✅ 🛠 playstation
✅ 🛠 🧪 unsafe-merge	✅ 🛠 tv	✅ 🧪 mac-intel-wk2
	✅ 🛠 tv-sim	✅ 🛠 mac-safer-cpp
	✅ 🛠 watch
	✅ 🛠 watch-sim

[rwlbuis]

LGTM.

[webkit-commit-queue]

Committed 304933@main (b43f2f0): https://commits.webkit.org/304933@main

Reviewed commits have been landed. Closing PR #55851 and removing active labels.