Implement scrollbar-gutter both-edges support on non-viewports

[lukewarlow]

9a055c1

Implement scrollbar-gutter both-edges support on non-viewports
https://bugs.webkit.org/show_bug.cgi?id=257708

Reviewed by Simon Fraser.

Scrollbar gutter now correctly works (on non-viewports) for both the
"stable" and "stable both-edges" values.

* LayoutTests/TestExpectations:
* LayoutTests/imported/w3c/web-platform-tests/css/css-overflow/scrollbar-gutter-001-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/css/css-overflow/scrollbar-gutter-rtl-001-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/css/css-overflow/scrollbar-gutter-vertical-lr-001-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/css/css-overflow/scrollbar-gutter-vertical-rl-001-expected.txt:
* Source/WebCore/rendering/RenderBlockFlow.cpp:
(WebCore::RenderBlockFlow::determineLogicalLeftPositionForChild):
* Source/WebCore/rendering/RenderBox.cpp:
(WebCore::RenderBox::contentBoxLocation const):
* Source/WebCore/rendering/RenderBoxInlines.h:
(WebCore::RenderBox::computedCSSContentBoxRect const):
(WebCore::RenderBox::contentHeight const):
(WebCore::RenderBox::contentWidth const):
(WebCore::RenderBox::overridingContentLogicalHeight const):
(WebCore::RenderBox::overridingContentLogicalWidth const):
* Source/WebCore/rendering/style/RenderStyle.h:

Canonical link: https://commits.webkit.org/265199@main

7efe6a9

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

[webkit-early-warning-system]

EWS run on previous version of this PR (hash d8ee448)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	❌ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	❌ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	❌ 🧪 ios-wk2	⏳ 🧪 api-mac	✅ 🛠 gtk
	❌ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
	❌ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	❌ 🛠 tv	✅ 🧪 mac-AS-debug-wk2
	❌ 🛠 tv-sim
	❌ 🛠 watch
	❌ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash e778618)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	❌ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	❌ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	❌ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	❌ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
	❌ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	❌ 🛠 tv	✅ 🧪 mac-AS-debug-wk2
	❌ 🛠 tv-sim
	❌ 🛠 watch
	❌ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash c3aa87b)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	❌ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	❌ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	❌ 🧪 ios-wk2	🧪 api-mac	✅ 🛠 gtk
	❌ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
	❌ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	❌ 🛠 tv	✅ 🧪 mac-AS-debug-wk2
	❌ 🛠 tv-sim
	❌ 🛠 watch
	❌ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 39173fa)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 tv-sim
❌ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-commit-queue]

This change contains multiple commits which are not squashed together, blocking PR #14666. Please squash the commits to land.

[webkit-early-warning-system]

EWS run on current version of this PR (hash 7efe6a9)

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

[webkit-commit-queue]

Committed 265199@main (9a055c1): https://commits.webkit.org/265199@main

Reviewed commits have been landed. Closing PR #14666 and removing active labels.