Extending the NthIndexCache to support caching for the type of index.

Source/core/css/SiblingTraversalStrategies.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 75 matching lines @@
 
     int count = 0;
     for (const Element* sibling = ElementTraversal::previousSibling(element); sibling; sibling = ElementTraversal::previousSibling(*sibling))
         count++;
 
     return count;
 }
 
 inline int DOMSiblingTraversalStrategy::countElementsOfTypeBefore(Element& element, const QualifiedName& type) const
 {
+    if (NthIndexCache* nthIndexCache = element.document().nthIndexCache())
+        return nthIndexCache->nthChildIndexOfType(element, type) - 1;
     int count = 0;
     for (const Element* sibling = ElementTraversal::previousSibling(element, HasTagName(type)); sibling; sibling = ElementTraversal::previousSibling(*sibling, HasTagName(type)))
         ++count;
     return count;
 }
 
 inline int DOMSiblingTraversalStrategy::countElementsAfter(Element& element) const
 {
     if (NthIndexCache* nthIndexCache = element.document().nthIndexCache())
         return nthIndexCache->nthLastChildIndex(element) - 1;
 
     int count = 0;
     for (const Element* sibling = ElementTraversal::nextSibling(element); sibling; sibling = ElementTraversal::nextSibling(*sibling))
         ++count;
     return count;
 }
 
 inline int DOMSiblingTraversalStrategy::countElementsOfTypeAfter(Element& element, const QualifiedName& type) const
 {
+    if (NthIndexCache* nthIndexCache = element.document().nthIndexCache())
+        return nthIndexCache->nthLastChildIndexOfType(element, type) - 1;
+
     int count = 0;
     for (const Element* sibling = ElementTraversal::nextSibling(element, HasTagName(type)); sibling; sibling = ElementTraversal::nextSibling(*sibling, HasTagName(type)))
         ++count;
     return count;
 }
 
 class ShadowDOMSiblingTraversalStrategy final {
     STACK_ALLOCATED();
 public:
     ShadowDOMSiblingTraversalStrategy(const WillBeHeapVector<RawPtrWillBeMember<Node>, 32>& siblings, int nth)
@@ skipping 113 matching lines @@
         if (m_siblings[i]->isElementNode() && toElement(m_siblings[i])->hasTagName(type))
             return ++count;
     }
 
     return count;
 }
 
 }
 
 #endif