Refactor SelectorChecker::BehaviorAtBoundary

Source/core/css/TreeBoundaryCrossingRules.cpp

Index: Source/core/css/TreeBoundaryCrossingRules.cpp
diff --git a/Source/core/css/TreeBoundaryCrossingRules.cpp b/Source/core/css/TreeBoundaryCrossingRules.cpp
index 4d3b123d3bcaeaaee00f1bf800be67571b2070e3..c3e908c6493a32fa41b9a0844372c3888af5fed8 100644
--- a/Source/core/css/TreeBoundaryCrossingRules.cpp
+++ b/Source/core/css/TreeBoundaryCrossingRules.cpp
@@ -76,18 +76,13 @@ void TreeBoundaryCrossingRules::collectTreeBoundaryCrossingRules(Element* elemen
     for (DocumentOrderedList::iterator it = m_scopingNodes.begin(); it != m_scopingNodes.end(); ++it) {
         const ContainerNode* scopingNode = toContainerNode(*it);
         CSSStyleSheetRuleSubSet* ruleSubSet = m_treeBoundaryCrossingRuleSetMap.get(scopingNode);
-        unsigned boundaryBehavior = SelectorChecker::ScopeContainsLastMatchedElement;
         bool isInnerTreeScope = element->treeScope().isInclusiveAncestorOf(scopingNode->treeScope());
 
-        // If a given scoping node is a shadow root, we should use ScopeIsShadowRoot.
-        if (scopingNode && scopingNode->isShadowRoot())
-            boundaryBehavior |= SelectorChecker::ScopeIsShadowRoot;
-
         CascadeOrder cascadeOrder = isInnerTreeScope ? innerCascadeOrder : outerCascadeOrder;
         for (CSSStyleSheetRuleSubSet::iterator it = ruleSubSet->begin(); it != ruleSubSet->end(); ++it) {
             CSSStyleSheet* parentStyleSheet = it->first;
             RuleSet* ruleSet = it->second.get();
-            collector.collectMatchingRules(MatchRequest(ruleSet, includeEmptyRules, scopingNode, parentStyleSheet), ruleRange, static_cast<SelectorChecker::BehaviorAtBoundary>(boundaryBehavior), ignoreCascadeScope, cascadeOrder);
+            collector.collectMatchingRules(MatchRequest(ruleSet, includeEmptyRules, scopingNode, parentStyleSheet), ruleRange, SelectorChecker::ScopeContainsLastMatchedElement, ignoreCascadeScope, cascadeOrder);
         }
         ++innerCascadeOrder;
         --outerCascadeOrder;