Have ChildNodeList subclass NodeList instead of LiveNodeList

Source/core/dom/ChildNodeList.h

Index: Source/core/dom/ChildNodeList.h
diff --git a/Source/core/dom/ChildNodeList.h b/Source/core/dom/ChildNodeList.h
index b62ea6e7982903a0a35d0e25e7a330a6e9850df1..b356cdfb5616f961da8fb5beae2a5dcca799d121 100644
--- a/Source/core/dom/ChildNodeList.h
+++ b/Source/core/dom/ChildNodeList.h
@@ -3,6 +3,7 @@
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2007 Apple Inc. All rights reserved.
+ * Copyright (C) 2014 Samsung Electronics. 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
@@ -24,12 +25,13 @@
 #ifndef ChildNodeList_h
 #define ChildNodeList_h
 
-#include "core/dom/LiveNodeList.h"
+#include "core/dom/NodeList.h"
+#include "core/html/CollectionIndexCache.h"
 #include "wtf/PassRefPtr.h"
 
 namespace WebCore {
 
-class ChildNodeList FINAL : public LiveNodeList {
+class ChildNodeList FINAL : public NodeList {
 public:
     static PassRefPtr<ChildNodeList> create(PassRefPtr<ContainerNode> rootNode)
     {
@@ -38,11 +40,28 @@ public:
 
     virtual ~ChildNodeList();
 
-protected:
+    // DOM API.
+    virtual unsigned length() const OVERRIDE { return m_collectionIndexCache.nodeCount(*this); }
+    virtual Node* item(unsigned index) const OVERRIDE { return m_collectionIndexCache.nodeAt(*this, index); }
+
+    // Non-DOM API.
+    void invalidateCache() { m_collectionIndexCache.invalidate(); }
+    ContainerNode* ownerNode() const { return m_parent.get(); }
+
+    // CollectionIndexCache API.
+    ContainerNode& rootNode() const { return *m_parent; }
+    bool canTraverseBackward() const { return true; }
+    Node* itemBefore(const Node* previousItem) const;
+    Node* traverseToFirstElement(const ContainerNode& root) const { return root.firstChild(); }
+    Node* traverseForwardToOffset(unsigned offset, Node& currentNode, unsigned& currentOffset, const ContainerNode& root) const;
+
+private:
     explicit ChildNodeList(PassRefPtr<ContainerNode> rootNode);
 
     virtual bool isChildNodeList() const OVERRIDE { return true; }
-    virtual bool nodeMatches(const Element&) const OVERRIDE;
+
+    RefPtr<ContainerNode> m_parent;
+    mutable CollectionIndexCache<ChildNodeList, Node> m_collectionIndexCache;
 };
 
 DEFINE_TYPE_CASTS(ChildNodeList, NodeList, nodeList, nodeList->isChildNodeList(), nodeList.isChildNodeList());