Add a first pass of a class descendant invalidator, and a containing RuleSetAnalyzer

Source/core/css/RuleFeature.cpp

Index: Source/core/css/RuleFeature.cpp
diff --git a/Source/core/css/RuleFeature.cpp b/Source/core/css/RuleFeature.cpp
index 7c8f160ae43f4d7445289aeda1ee292c72301f55..9ef1f2f50c2a245db33575b9d81df539330383c7 100644
--- a/Source/core/css/RuleFeature.cpp
+++ b/Source/core/css/RuleFeature.cpp
@@ -35,13 +35,15 @@
 
 namespace WebCore {
 
-void RuleFeatureSet::collectFeaturesFromSelector(const CSSSelector* selector)
+void RuleFeatureSet::collectFeaturesFromSelector(const CSSSelector* selector, HashSet<AtomicString>* classesInRulesArg)
 {
     if (selector->m_match == CSSSelector::Id)
         idsInRules.add(selector->value());
-    else if (selector->m_match == CSSSelector::Class)
+    else if (selector->m_match == CSSSelector::Class) {
         classesInRules.add(selector->value());
-    else if (selector->isAttributeSelector())
+        if (classesInRulesArg)
+            classesInRulesArg->add(selector->value());
+    } else if (selector->isAttributeSelector())
         attrsInRules.add(selector->attribute().localName());
     switch (selector->pseudoType()) {
     case CSSSelector::PseudoFirstLine:
@@ -49,26 +51,29 @@ void RuleFeatureSet::collectFeaturesFromSelector(const CSSSelector* selector)
         break;
         break;
     case CSSSelector::PseudoHost:
-        collectFeaturesFromSelectorList(selector->selectorList());
+        collectFeaturesFromSelectorList(selector->selectorList(), classesInRulesArg);
         break;
     default:
         break;
     }
 }
 
-void RuleFeatureSet::collectFeaturesFromSelectorList(const CSSSelectorList* selectorList)
+void RuleFeatureSet::collectFeaturesFromSelectorList(const CSSSelectorList* selectorList, HashSet<AtomicString>* classesInRulesArg)
 {
     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);
+            collectFeaturesFromSelector(subSelector, classesInRulesArg);
     }
 }
 
 void RuleFeatureSet::add(const RuleFeatureSet& other)
 {
+    if (RuleSetAnalyzer* otherAnalyzer = other.getRuleSetAnalyzer())
+        ensureRuleSetAnalyzer()->combine(*otherAnalyzer);
+
     HashSet<AtomicString>::const_iterator end = other.idsInRules.end();
     for (HashSet<AtomicString>::const_iterator it = other.idsInRules.begin(); it != end; ++it)
         idsInRules.add(*it);
@@ -95,4 +100,16 @@ void RuleFeatureSet::clear()
     m_maxDirectAdjacentSelectors = 0;
 }
 
+RuleSetAnalyzer* RuleFeatureSet::getRuleSetAnalyzer() const
+{
+    return ruleSetAnalyzer.get();
+}
+
+RuleSetAnalyzer* RuleFeatureSet::ensureRuleSetAnalyzer()
+{
+    if (!ruleSetAnalyzer)
+        ruleSetAnalyzer = RuleSetAnalyzer::create();
+    return ruleSetAnalyzer.get();
+}
+
 } // namespace WebCore