Only cache nth-indices when child count > 32.

third_party/WebKit/Source/core/css/SelectorChecker.cpp

Index: third_party/WebKit/Source/core/css/SelectorChecker.cpp
diff --git a/third_party/WebKit/Source/core/css/SelectorChecker.cpp b/third_party/WebKit/Source/core/css/SelectorChecker.cpp
index 771468302c6177825cb2a1575bbdfb6f0a2807ac..54bdea3e302aa62b729635c33aac86f49e86cf0b 100644
--- a/third_party/WebKit/Source/core/css/SelectorChecker.cpp
+++ b/third_party/WebKit/Source/core/css/SelectorChecker.cpp
@@ -180,50 +180,6 @@ static bool isLastOfType(Element& element, const QualifiedName& type)
     return !ElementTraversal::nextSibling(element, HasTagName(type));
 }
 
-static int nthChildIndex(Element& element)
-{
-    if (NthIndexCache* nthIndexCache = element.document().nthIndexCache())
-        return nthIndexCache->nthChildIndex(element);
-
-    int index = 1;
-    for (const Element* sibling = ElementTraversal::previousSibling(element); sibling; sibling = ElementTraversal::previousSibling(*sibling))
-        index++;
-
-    return index;
-}
-
-static int nthOfTypeIndex(Element& element, const QualifiedName& type)
-{
-    if (NthIndexCache* nthIndexCache = element.document().nthIndexCache())
-        return nthIndexCache->nthChildIndexOfType(element, type);
-    int index = 1;
-    for (const Element* sibling = ElementTraversal::previousSibling(element, HasTagName(type)); sibling; sibling = ElementTraversal::previousSibling(*sibling, HasTagName(type)))
-        ++index;
-    return index;
-}
-
-static int nthLastChildIndex(Element& element)
-{
-    if (NthIndexCache* nthIndexCache = element.document().nthIndexCache())
-        return nthIndexCache->nthLastChildIndex(element);
-
-    int index = 1;
-    for (const Element* sibling = ElementTraversal::nextSibling(element); sibling; sibling = ElementTraversal::nextSibling(*sibling))
-        ++index;
-    return index;
-}
-
-static int nthLastOfTypeIndex(Element& element, const QualifiedName& type)
-{
-    if (NthIndexCache* nthIndexCache = element.document().nthIndexCache())
-        return nthIndexCache->nthLastChildIndexOfType(element, type);
-
-    int index = 1;
-    for (const Element* sibling = ElementTraversal::nextSibling(element, HasTagName(type)); sibling; sibling = ElementTraversal::nextSibling(*sibling, HasTagName(type)))
-        ++index;
-    return index;
-}
-
 // Recursive check of selectors and combinators
 // It can return 4 different values:
 // * SelectorMatches          - the selector matches the element e
@@ -770,14 +726,14 @@ bool SelectorChecker::checkPseudoClass(const SelectorCheckingContext& context, M
         if (ContainerNode* parent = element.parentElementOrDocumentFragment()) {
             if (m_mode == ResolvingStyle)
                 parent->setChildrenAffectedByForwardPositionalRules();
-            return selector.matchNth(nthChildIndex(element));
+            return selector.matchNth(NthIndexCache::nthChildIndex(element));
         }
         break;
     case CSSSelector::PseudoNthOfType:
         if (ContainerNode* parent = element.parentElementOrDocumentFragment()) {
             if (m_mode == ResolvingStyle)
                 parent->setChildrenAffectedByForwardPositionalRules();
-            return selector.matchNth(nthOfTypeIndex(element, element.tagQName()));
+            return selector.matchNth(NthIndexCache::nthOfTypeIndex(element));
         }
         break;
     case CSSSelector::PseudoNthLastChild:
@@ -786,7 +742,7 @@ bool SelectorChecker::checkPseudoClass(const SelectorCheckingContext& context, M
                 parent->setChildrenAffectedByBackwardPositionalRules();
             if (!parent->isFinishedParsingChildren())
                 return false;
-            return selector.matchNth(nthLastChildIndex(element));
+            return selector.matchNth(NthIndexCache::nthLastChildIndex(element));
         }
         break;
     case CSSSelector::PseudoNthLastOfType:
@@ -795,7 +751,7 @@ bool SelectorChecker::checkPseudoClass(const SelectorCheckingContext& context, M
                 parent->setChildrenAffectedByBackwardPositionalRules();
             if (!parent->isFinishedParsingChildren())
                 return false;
-            return selector.matchNth(nthLastOfTypeIndex(element, element.tagQName()));
+            return selector.matchNth(NthIndexCache::nthLastOfTypeIndex(element));
         }
         break;
     case CSSSelector::PseudoTarget: