Change shadow style's scope from Shadow Host to Shadow Root

Source/core/css/ElementRuleCollector.cpp

Index: Source/core/css/ElementRuleCollector.cpp
diff --git a/Source/core/css/ElementRuleCollector.cpp b/Source/core/css/ElementRuleCollector.cpp
index 13cde17e4d5cf08672fe568979d2484f511951c0..79ef923b697f87f6b70bc7ec3b5138a0efa88a02 100644
--- a/Source/core/css/ElementRuleCollector.cpp
+++ b/Source/core/css/ElementRuleCollector.cpp
@@ -130,7 +130,7 @@ static bool rulesApplicableInCurrentTreeScope(const Element* element, const Cont
     if (!scopingNode || treeScope == scopingNode->treeScope())
         return true;
     // d) the rules comes from a scoped style sheet within an active shadow root whose host is the given element
-    if (element->isInShadowTree() && (behaviorAtBoundary & SelectorChecker::ScopeIsShadowHost) && scopingNode == element->containingShadowRoot()->host())
+    if (SelectorChecker::isHostInItsShadowTree(*element, behaviorAtBoundary, scopingNode))
         return true;
     return false;
 }