[CSS Nesting] Rebuild rule set from original (not resolved) selector

https://bugs.webkit.org/show_bug.cgi?id=255521
rdar://108137916

Reviewed by Antti Koivisto.

When there is a modification of a selector by CSSOM,
the next resolution should work on the original user-written selector,
not on the previously resolved selector.

* LayoutTests/imported/w3c/web-platform-tests/css/css-nesting/invalidation-004-expected.txt:
* Source/WebCore/style/RuleSetBuilder.cpp:
(WebCore::Style::RuleSetBuilder::resolveSelectorListWithNesting):

Canonical link: https://commits.webkit.org/263026@main

LayoutTests/imported/w3c/web-platform-tests/css/css-nesting/invalidation-004-expected.txt

@@ -1,4 +1,4 @@
 Test passes if color is green.
 
-FAIL CSS Selectors nested invalidation through @media by selectorText assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
+PASS CSS Selectors nested invalidation through @media by selectorText
 

Source/WebCore/style/RuleSetBuilder.cpp

@@ -221,11 +221,11 @@ void RuleSetBuilder::resolveSelectorListWithNesting(StyleRuleWithNesting& rule)
     if (m_styleRuleStack.size()) 
         parentResolvedSelectorList =  m_styleRuleStack.last();
 
-    // If it's a top-level rule wihout a nesting parent selector, keep the selector list as is.
-    if (!rule.selectorList().hasExplicitNestingParent() && !parentResolvedSelectorList)
+    // If it's a top-level rule without a nesting parent selector, keep the selector list as is.
+    if (!rule.originalSelectorList().hasExplicitNestingParent() && !parentResolvedSelectorList)
         return;
 
-    auto resolvedSelectorList = CSSSelectorParser::resolveNestingParent(rule.selectorList(), parentResolvedSelectorList);
+    auto resolvedSelectorList = CSSSelectorParser::resolveNestingParent(rule.originalSelectorList(), parentResolvedSelectorList);
     ASSERT(!resolvedSelectorList.hasExplicitNestingParent());
     rule.wrapperAdoptSelectorList(WTFMove(resolvedSelectorList));    
 }