Have ElementRuleCollector keep match result vector as part object.

Source/core/css/ElementRuleCollector.cpp

Index: Source/core/css/ElementRuleCollector.cpp
diff --git a/Source/core/css/ElementRuleCollector.cpp b/Source/core/css/ElementRuleCollector.cpp
index d7c7a0e596bc0ab06ef9ca89b5d1db75176712e3..0c739f4724a1fd4725f0785e860c90f706745713 100644
--- a/Source/core/css/ElementRuleCollector.cpp
+++ b/Source/core/css/ElementRuleCollector.cpp
@@ -81,16 +81,12 @@ PassRefPtrWillBeRawPtr<CSSRuleList> ElementRuleCollector::matchedCSSRuleList()
 
 inline void ElementRuleCollector::addMatchedRule(const RuleData* rule, unsigned specificity, CascadeScope cascadeScope, CascadeOrder cascadeOrder, unsigned styleSheetIndex, const CSSStyleSheet* parentStyleSheet)
 {
-    if (!m_matchedRules)
-        m_matchedRules = adoptPtrWillBeNoop(new WillBeHeapVector<MatchedRule, 32>);
-    m_matchedRules->append(MatchedRule(rule, specificity, cascadeScope, cascadeOrder, styleSheetIndex, parentStyleSheet));
+    m_matchedRules.append(MatchedRule(rule, specificity, cascadeScope, cascadeOrder, styleSheetIndex, parentStyleSheet));
 }
 
 void ElementRuleCollector::clearMatchedRules()
 {
-    if (!m_matchedRules)
-        return;
-    m_matchedRules->clear();
+    m_matchedRules.clear();
 }
 
 inline StyleRuleList* ElementRuleCollector::ensureStyleRuleList()
@@ -227,12 +223,12 @@ void ElementRuleCollector::appendCSSOMWrapperForRule(CSSStyleSheet* parentStyleS
 
 void ElementRuleCollector::sortAndTransferMatchedRules()
 {
-    if (!m_matchedRules || m_matchedRules->isEmpty())
+    if (m_matchedRules.isEmpty())
         return;
 
     sortMatchedRules();
 
-    WillBeHeapVector<MatchedRule, 32>& matchedRules = *m_matchedRules;
+    WillBeHeapVector<MatchedRule, 32>& matchedRules = m_matchedRules;

[rune, 2014/12/12 07:10:35]

Is it really necessary to have a new reference here? Couldn't m_matchedRules be
used directly below?

[sof, 2014/12/12 07:13:23]

Yes, we can simplify this away now. Will do.

     if (m_mode == SelectorChecker::CollectingStyleRules) {
         for (unsigned i = 0; i < matchedRules.size(); ++i)
             ensureStyleRuleList()->m_list.append(matchedRules[i].ruleData()->rule());
@@ -330,8 +326,7 @@ static inline bool compareRules(const MatchedRule& matchedRule1, const MatchedRu
 
 void ElementRuleCollector::sortMatchedRules()
 {
-    ASSERT(m_matchedRules);
-    std::sort(m_matchedRules->begin(), m_matchedRules->end(), compareRules);
+    std::sort(m_matchedRules.begin(), m_matchedRules.end(), compareRules);
 }
 
 bool ElementRuleCollector::hasAnyMatchingRules(RuleSet* ruleSet)
@@ -347,7 +342,7 @@ bool ElementRuleCollector::hasAnyMatchingRules(RuleSet* ruleSet)
     // FIXME: Verify whether it's ok to ignore CascadeScope here.
     collectMatchingRules(MatchRequest(ruleSet), ruleRange);
 
-    return m_matchedRules && !m_matchedRules->isEmpty();
+    return !m_matchedRules.isEmpty();
 }
 
 } // namespace blink