Support a negation pseudo-class, :not(), in <content select>

Source/core/html/HTMLContentElement.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 65 matching lines @@
     if (name == selectAttr) {
         if (ShadowRoot* root = containingShadowRoot())
             root->owner()->willAffectSelector();
         m_shouldParseSelect = true;
         m_select = value;
     } else {
         InsertionPoint::parseAttribute(name, value);
     }
 }
 
+static inline bool includesDisallowedPseudoClass(const CSSSelector& selector)
+{
+    return selector.m_match == CSSSelector::PseudoClass && selector.m_pseudoType != CSSSelector::PseudoNot;
+}
+
 bool HTMLContentElement::validateSelect() const
 {
     ASSERT(!m_shouldParseSelect);
 
     if (m_select.isNull() || m_select.isEmpty())
         return true;
 
     if (!m_selectorList.isValid())
         return false;
 
-    bool disallowPseudoClasses = !RuntimeEnabledFeatures::pseudoClassesInMatchingCriteriaInAuthorShadowTreesEnabled() && containingShadowRoot() && containingShadowRoot()->type() == ShadowRoot::AuthorShadowRoot;
+    bool allowAnyPseudoClasses = RuntimeEnabledFeatures::pseudoClassesInMatchingCriteriaInAuthorShadowTreesEnabled() || (containingShadowRoot() && containingShadowRoot()->type() == ShadowRoot::UserAgentShadowRoot);
 
     for (const CSSSelector* selector = m_selectorList.first(); selector; selector = m_selectorList.next(*selector)) {
         if (!selector->isCompound())
             return false;
-        if (!disallowPseudoClasses)
+        if (allowAnyPseudoClasses)
             continue;
         for (const CSSSelector* subSelector = selector; subSelector; subSelector = subSelector->tagHistory()) {
-            if (subSelector->m_match == CSSSelector::PseudoClass)
+            if (includesDisallowedPseudoClass(*subSelector))
                 return false;
         }
     }
     return true;
 }
 
 static inline bool checkOneSelector(const CSSSelector& selector, const WillBeHeapVector<RawPtrWillBeMember<Node>, 32>& siblings, int nth)
 {
     Element* element = toElement(siblings[nth]);
     SelectorChecker selectorChecker(element->document(), SelectorChecker::CollectingCSSRules);
     SelectorChecker::SelectorCheckingContext context(selector, element, SelectorChecker::VisitedMatchEnabled);
     ShadowDOMSiblingTraversalStrategy strategy(siblings, nth);
     return selectorChecker.match(context, strategy) == SelectorChecker::SelectorMatches;
 }
 
 bool HTMLContentElement::matchSelector(const WillBeHeapVector<RawPtrWillBeMember<Node>, 32>& siblings, int nth) const
 {
     for (const CSSSelector* selector = selectorList().first(); selector; selector = CSSSelectorList::next(*selector)) {
         if (checkOneSelector(*selector, siblings, nth))
             return true;
     }
     return false;
 }
 
 }