Stop passing the root node to node lists traversal functions

Source/core/dom/LiveNodeListBase.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.
  * 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
  * License as published by the Free Software Foundation; either
@@ skipping 69 matching lines @@
     static bool shouldInvalidateTypeOnAttributeChange(NodeListInvalidationType, const QualifiedName&);
 
 protected:
     Document& document() const { return m_ownerNode->document(); }
 
     ALWAYS_INLINE NodeListRootType rootType() const { return static_cast<NodeListRootType>(m_rootType); }
 
     template <typename Collection>
     static Element* itemBefore(const Collection&, const Element* previousItem);
     template <class NodeListType>
-    static Element* firstMatchingElement(const NodeListType&, const ContainerNode&);
+    static Element* firstMatchingElement(const NodeListType&);
     template <class NodeListType>
-    static Element* nextMatchingElement(const NodeListType&, Element& current, const ContainerNode& root);
+    static Element* nextMatchingElement(const NodeListType&, Element& current);
     template <class NodeListType>
-    static Element* traverseMatchingElementsForwardToOffset(const NodeListType&, unsigned offset, Element& currentElement, unsigned& currentOffset, const ContainerNode& root);
+    static Element* traverseMatchingElementsForwardToOffset(const NodeListType&, unsigned offset, Element& currentElement, unsigned& currentOffset);
 
 private:
     void invalidateIdNameCacheMaps() const;
     template <typename Collection>
     static Element* iterateForPreviousNode(const Collection&, Node* current);
     static Node* previousNode(const ContainerNode&, const Node& previous, bool onlyIncludeDirectChildren);
     static Node* lastDescendant(const ContainerNode&);
     static Node* lastNode(const ContainerNode&, bool onlyIncludeDirectChildren);
 
     RefPtr<ContainerNode> m_ownerNode; // Cannot be null.
@@ skipping 62 matching lines @@
     Node* current;
     if (LIKELY(!!previous)) // Without this LIKELY, length() and item() can be 10% slower.
         current = previousNode(collection.rootNode(), *previous, collection.shouldOnlyIncludeDirectChildren());
     else
         current = lastNode(collection.rootNode(), collection.shouldOnlyIncludeDirectChildren());
 
     return iterateForPreviousNode(collection, current);
 }
 
 template <class NodeListType>
-Element* LiveNodeListBase::firstMatchingElement(const NodeListType& nodeList, const ContainerNode& root)
+Element* LiveNodeListBase::firstMatchingElement(const NodeListType& nodeList)
 {
+    ContainerNode& root = nodeList.rootNode();
     Element* element = ElementTraversal::firstWithin(root);
     while (element && !isMatchingElement(nodeList, *element))
         element = ElementTraversal::next(*element, &root);
     return element;
 }
 
 template <class NodeListType>
-Element* LiveNodeListBase::nextMatchingElement(const NodeListType& nodeList, Element& current, const ContainerNode& root)
+Element* LiveNodeListBase::nextMatchingElement(const NodeListType& nodeList, Element& current)
 {
+    ContainerNode& root = nodeList.rootNode();
     Element* next = &current;
     do {
         next = ElementTraversal::next(*next, &root);
     } while (next && !isMatchingElement(nodeList, *next));
     return next;
 }
 
 template <class NodeListType>
-Element* LiveNodeListBase::traverseMatchingElementsForwardToOffset(const NodeListType& nodeList, unsigned offset, Element& currentElement, unsigned& currentOffset, const ContainerNode& root)
+Element* LiveNodeListBase::traverseMatchingElementsForwardToOffset(const NodeListType& nodeList, unsigned offset, Element& currentElement, unsigned& currentOffset)
 {
     ASSERT(currentOffset < offset);
     Element* next = &currentElement;
-    while ((next = nextMatchingElement(nodeList, *next, root))) {
+    while ((next = nextMatchingElement(nodeList, *next))) {
         if (++currentOffset == offset)
             return next;
     }
     return 0;
 }
 
 } // namespace WebCore
 
 #endif // LiveNodeListBase_h