[CSS-Flexbox] Fallback to 'safe center' for 'align-content'

[Ahmad-S792]

95238f7

[CSS-Flexbox] Fallback to 'safe center' for 'align-content'
https://bugs.webkit.org/show_bug.cgi?id=294506
rdar://153403381

Reviewed by Alan Baradlay.

This patch aligns WebKit with Web Specification [1] & [2]:

[1] https://www.w3.org/TR/css-align-3/#valdef-align-content-space-around
[2] https://www.w3.org/TR/css-align-3/#valdef-align-content-space-evenly

For both 'space-around' and 'space-evenly', the default fallback alignment
is 'space center'.

This patch clamps the value to 'non-negative' by using `std::max`.

* Source/WebCore/rendering/RenderFlexibleBox.cpp:
(WebCore::initialAlignContentOffset):
* LayoutTests/imported/w3c/web-platform-tests/css/css-flexbox/align-content-wrap-003-expected.txt: Progression

Canonical link: https://commits.webkit.org/296239@main

5df82f2

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[webkit-early-warning-system]

Starting EWS tests for 7a39f35. Live statuses available at the PR page, #46763

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 7a39f35)

Details

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✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	⏳ 🧪 win-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-cairo
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	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
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	✅ 🛠 tv-sim
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	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash 5df82f2)

Details

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

[webkit-commit-queue]

Committed 296239@main (95238f7): https://commits.webkit.org/296239@main

Reviewed commits have been landed. Closing PR #46763 and removing active labels.