Use Ref<> for MatchedProperties::properties instead of RefPtr<>

[cdumez]

f1c09f6

Use Ref<> for MatchedProperties::properties instead of RefPtr<>
https://bugs.webkit.org/show_bug.cgi?id=259092

Reviewed by Tim Nguyen.

Use Ref<> for MatchedProperties::properties instead of RefPtr<>, to make it
clear it cannot be null.

* Source/WebCore/style/ElementRuleCollector.cpp:
(WebCore::Style::ElementRuleCollector::addElementStyleProperties):
(WebCore::Style::ElementRuleCollector::transferMatchedRules):
(WebCore::Style::ElementRuleCollector::matchAllRules):
(WebCore::Style::ElementRuleCollector::addMatchedProperties):
(WebCore::Style::ElementRuleCollector::addAuthorKeyframeRules):
* Source/WebCore/style/MatchResult.h:
(WebCore::Style::operator==):
(WebCore::Style::add):
* Source/WebCore/style/PageRuleCollector.cpp:
(WebCore::Style::PageRuleCollector::matchPageRules):
* Source/WebCore/style/PropertyCascade.cpp:
(WebCore::Style::PropertyCascade::addMatch):
(WebCore::Style::PropertyCascade::addImportantMatches):

Canonical link: https://commits.webkit.org/265936@main

77c05f2

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-early-warning-system]

EWS run on current version of this PR (hash 77c05f2)

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]

Committed 265936@main (f1c09f6): https://commits.webkit.org/265936@main

Reviewed commits have been landed. Closing PR #15724 and removing active labels.