Remove needsShadowTreeWalker flag

Source/core/dom/ContainerNode.h

Index: Source/core/dom/ContainerNode.h
diff --git a/Source/core/dom/ContainerNode.h b/Source/core/dom/ContainerNode.h
index da683f2197ddfa8bdde1c68f6baeee576a0d9411..e25b30826bc3ec4efe27958568601e0d59142fb6 100644
--- a/Source/core/dom/ContainerNode.h
+++ b/Source/core/dom/ContainerNode.h
@@ -263,14 +263,6 @@ inline Node* Node::highestAncestor() const
     return highest;
 }
 
-inline bool Node::needsShadowTreeWalker() const
-{
-    if (getFlag(NeedsShadowTreeWalkerFlag))
-        return true;
-    ContainerNode* parent = parentOrShadowHostNode();
-    return parent && parent->getFlag(NeedsShadowTreeWalkerFlag);
-}
-
 // This constant controls how much buffer is initially allocated
 // for a Node Vector that is used to store child Nodes of a given Node.
 // FIXME: Optimize the value.