Move m_overridesItemAfter member from LiveNodeListBase to HTMLCollection

Source/core/dom/LiveNodeList.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 26 matching lines @@
 class Element;
 
 enum NodeListRootType {
     NodeListIsRootedAtNode,
     NodeListIsRootedAtDocument,
     NodeListIsRootedAtDocumentIfOwnerHasItemrefAttr,
 };
 
 class LiveNodeListBase {
 public:
-    enum ItemAfterOverrideType {
-        OverridesItemAfter,
-        DoesNotOverrideItemAfter,
-    };
-
     LiveNodeListBase(ContainerNode* ownerNode, NodeListRootType rootType, NodeListInvalidationType invalidationType,
-        bool shouldOnlyIncludeDirectChildren, CollectionType collectionType, ItemAfterOverrideType itemAfterOverrideType)
+        bool shouldOnlyIncludeDirectChildren, CollectionType collectionType)
         : m_ownerNode(ownerNode)
         , m_rootType(rootType)
         , m_invalidationType(invalidationType)
         , m_shouldOnlyIncludeDirectChildren(shouldOnlyIncludeDirectChildren)
         , m_collectionType(collectionType)
-        , m_overridesItemAfter(itemAfterOverrideType == OverridesItemAfter)
     {
         ASSERT(m_ownerNode);
         ASSERT(m_rootType == static_cast<unsigned>(rootType));
         ASSERT(m_invalidationType == static_cast<unsigned>(invalidationType));
         ASSERT(m_collectionType == static_cast<unsigned>(collectionType));
-        ASSERT(!m_overridesItemAfter || !isLiveNodeListType(collectionType));
 
         if (collectionType != ChildNodeListType)
             document().registerNodeList(this);
     }
 
     virtual ~LiveNodeListBase()
     {
         if (type() != ChildNodeListType)
             document().unregisterNodeList(this);
     }
 
     ContainerNode& rootNode() const;
-    bool overridesItemAfter() const { return m_overridesItemAfter; }
     Node* itemBefore(const Node* previousItem) const;
 
     ALWAYS_INLINE bool hasIdNameCache() const { return !isLiveNodeListType(type()); }
     ALWAYS_INLINE bool isRootedAtDocument() const { return m_rootType == NodeListIsRootedAtDocument || m_rootType == NodeListIsRootedAtDocumentIfOwnerHasItemrefAttr; }
     ALWAYS_INLINE NodeListInvalidationType invalidationType() const { return static_cast<NodeListInvalidationType>(m_invalidationType); }
     ALWAYS_INLINE CollectionType type() const { return static_cast<CollectionType>(m_collectionType); }
     ContainerNode* ownerNode() const { return m_ownerNode.get(); }
     ALWAYS_INLINE void invalidateCache(const QualifiedName* attrName) const
     {
         if (!attrName || shouldInvalidateTypeOnAttributeChange(invalidationType(), *attrName))
@@ skipping 13 matching lines @@
 
 private:
     Node* iterateForPreviousNode(Node* current) const;
     void invalidateIdNameCacheMaps() const;
 
     RefPtr<ContainerNode> m_ownerNode; // Cannot be null.
     const unsigned m_rootType : 2;
     const unsigned m_invalidationType : 4;
     const unsigned m_shouldOnlyIncludeDirectChildren : 1;
     const unsigned m_collectionType : 5;
-
-    // From HTMLCollection
-    const unsigned m_overridesItemAfter : 1;
 };
 
 ALWAYS_INLINE bool LiveNodeListBase::shouldInvalidateTypeOnAttributeChange(NodeListInvalidationType type, const QualifiedName& attrName)
 {
     switch (type) {
     case InvalidateOnClassAttrChange:
         return attrName == HTMLNames::classAttr;
     case InvalidateOnNameAttrChange:
         return attrName == HTMLNames::nameAttr;
     case InvalidateOnIdNameAttrChange:
@@ skipping 11 matching lines @@
     case InvalidateOnAnyAttrChange:
         return true;
     }
     return false;
 }
 
 class LiveNodeList : public NodeList, public LiveNodeListBase {
 public:
     LiveNodeList(PassRefPtr<ContainerNode> ownerNode, CollectionType collectionType, NodeListInvalidationType invalidationType, NodeListRootType rootType = NodeListIsRootedAtNode)
         : LiveNodeListBase(ownerNode.get(), rootType, invalidationType, collectionType == ChildNodeListType,
-        collectionType, DoesNotOverrideItemAfter)
+        collectionType)
     { }
 
     virtual unsigned length() const OVERRIDE FINAL { return m_collectionIndexCache.nodeCount(*this); }
     virtual Node* item(unsigned offset) const OVERRIDE FINAL { return m_collectionIndexCache.nodeAt(*this, offset); }
     virtual Node* namedItem(const AtomicString&) const OVERRIDE FINAL;
     virtual bool nodeMatches(const Element&) const = 0;
     // Avoid ambiguity since both NodeList and LiveNodeListBase have an ownerNode() method.
     using LiveNodeListBase::ownerNode;
 
     virtual void invalidateCache() const OVERRIDE FINAL;
 
     // Collection IndexCache API.
+    bool canTraverseBackward() const { return true; }
     Node* traverseToFirstElement(const ContainerNode& root) const;
     Node* traverseForwardToOffset(unsigned offset, Node& currentNode, unsigned& currentOffset, const ContainerNode& root) const;
 
 private:
     virtual bool isLiveNodeList() const OVERRIDE FINAL { return true; }
 
     mutable CollectionIndexCache<LiveNodeList> m_collectionIndexCache;
 };
 
 } // namespace WebCore
 
 #endif // LiveNodeList_h