Removed O(n!) traversal of selectors for selectorList.

Source/core/css/RuleFeature.cpp

 /*
  * 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, 2012 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 193 matching lines @@
     }
 
     ASSERT(!maxDirectAdjacentSelectors);
 }
 
 void RuleFeatureSet::collectFeaturesFromSelectorList(const CSSSelectorList* selectorList, RuleFeatureSet::FeatureMetadata& metadata, SelectorFeatureCollectionMode collectionMode)
 {
     if (!selectorList)
         return;
 
-    for (const CSSSelector* selector = selectorList->first(); selector; selector = CSSSelectorList::next(*selector)) {
-        for (const CSSSelector* subSelector = selector; subSelector; subSelector = subSelector->tagHistory())
-            collectFeaturesFromSelector(*subSelector, metadata, collectionMode);
-    }
+    for (const CSSSelector* selector = selectorList->first(); selector; selector = CSSSelectorList::next(*selector))
+        collectFeaturesFromSelector(*selector, metadata, collectionMode);
 }
 
 void RuleFeatureSet::FeatureMetadata::add(const FeatureMetadata& other)
 {
     usesFirstLineRules = usesFirstLineRules || other.usesFirstLineRules;
     maxDirectAdjacentSelectors = std::max(maxDirectAdjacentSelectors, other.maxDirectAdjacentSelectors);
 
     HashSet<AtomicString>::const_iterator end = other.idsInRules.end();
     for (HashSet<AtomicString>::const_iterator it = other.idsInRules.begin(); it != end; ++it)
         idsInRules.add(*it);
@@ skipping 196 matching lines @@
         element->setNeedsStyleRecalc(LocalStyleChange);
 
     invalidationClasses.remove(oldSize, invalidationClasses.size() - oldSize);
     element->clearChildNeedsStyleInvalidation();
     element->clearNeedsStyleInvalidation();
 
     return thisElementNeedsStyleRecalc;
 }
 
 } // namespace WebCore