Only support AddFeatures invalidation set mode for :host or :any in a rightmost selector

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 85 matching lines @@
     case CSSSelector::PseudoInRange:
     case CSSSelector::PseudoOutOfRange:
     case CSSSelector::PseudoUnresolved:
         return true;
     default:
         return false;
     }
 }
 
 // This method is somewhat conservative in what it accepts.
-RuleFeatureSet::InvalidationSetMode RuleFeatureSet::supportsClassDescendantInvalidation(const CSSSelector& selector)
+RuleFeatureSet::InvalidationSetMode RuleFeatureSet::getInvalidationSetMode(const CSSSelector& selector)
 {
     bool foundDescendantRelation = false;
     bool foundIdent = false;
     for (const CSSSelector* component = &selector; component; component = component->tagHistory()) {
 
         // FIXME: next up: Tag and Id.
         if (component->m_match == CSSSelector::Class || component->isAttributeSelector()) {
             if (!foundDescendantRelation)
                 foundIdent = true;
         } else if (component->pseudoType() == CSSSelector::PseudoHost || component->pseudoType() == CSSSelector::PseudoAny) {
             if (const CSSSelectorList* selectorList = component->selectorList()) {
                 for (const CSSSelector* selector = selectorList->first(); selector; selector = CSSSelectorList::next(*selector)) {
-                    InvalidationSetMode hostMode = supportsClassDescendantInvalidation(*selector);
+                    InvalidationSetMode hostMode = getInvalidationSetMode(*selector);
                     if (hostMode == UseSubtreeStyleChange)
                         return foundDescendantRelation ? UseLocalStyleChange : UseSubtreeStyleChange;
-                    if (hostMode == AddFeatures)
+                    if (!foundDescendantRelation && hostMode == AddFeatures)
                         foundIdent = true;
                 }
             }
         } else if (!isSkippableComponentForInvalidation(*component)) {
             return foundDescendantRelation ? UseLocalStyleChange : UseSubtreeStyleChange;
         }
         switch (component->relation()) {
         case CSSSelector::Descendant:
         case CSSSelector::Child:
         case CSSSelector::ShadowPseudo:
@@ skipping 30 matching lines @@
 {
     if (selector.m_match == CSSSelector::Class)
         return &ensureClassInvalidationSet(selector.value());
     if (selector.isAttributeSelector())
         return &ensureAttributeInvalidationSet(selector.attribute().localName());
     return 0;
 }
 
 RuleFeatureSet::InvalidationSetMode RuleFeatureSet::updateInvalidationSets(const CSSSelector& selector)
 {
-    InvalidationSetMode mode = supportsClassDescendantInvalidation(selector);
+    InvalidationSetMode mode = getInvalidationSetMode(selector);
     if (mode != AddFeatures)
         return mode;
 
     InvalidationSetFeatures features;
     const CSSSelector* current = extractInvalidationSetFeatures(selector, features);
     if (current)
         current = current->tagHistory();
 
     if (current)
         addFeaturesToInvalidationSets(*current, features);
@@ skipping 219 matching lines @@
     if (RefPtr<DescendantInvalidationSet> invalidationSet = m_classInvalidationSets.get(className))
         m_styleInvalidator.scheduleInvalidation(invalidationSet, element);
 }
 
 StyleInvalidator& RuleFeatureSet::styleInvalidator()
 {
     return m_styleInvalidator;
 }
 
 } // namespace WebCore