Backend for css rule tracking

third_party/WebKit/Source/core/css/ElementRuleCollector.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc.
  * All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 125 matching lines @@
   void finishAddingUARules() { m_result.finishAddingUARules(); }
   void finishAddingAuthorRulesForTreeScope() {
     m_result.finishAddingAuthorRulesForTreeScope();
   }
   void setIncludeEmptyRules(bool include) { m_includeEmptyRules = include; }
   bool includeEmptyRules() const { return m_includeEmptyRules; }
   bool isCollectingForPseudoElement() const {
     return m_pseudoStyleRequest.pseudoId != PseudoIdNone;
   }
 
+  const HeapVector<MatchedRule, 32>& matchedRulesList() const {

[pfeldman, 2016/11/03 21:23:30]

I don't think you should expose otherwise encapsulated list. There is a better
alternative:

void reportUsage(Tracker tracker)

+    return m_matchedRules;
+  }
+
  private:
   template <typename RuleDataListType>
   void collectMatchingRulesForList(const RuleDataListType*,
                                    CascadeOrder,
                                    const MatchRequest&);
 
   void didMatchRule(const RuleData&,
                     const SelectorChecker::MatchResult&,
                     CascadeOrder,
                     const MatchRequest&);
@@ skipping 23 matching lines @@
 
   // Output.
   Member<StaticCSSRuleList> m_cssRuleList;
   Member<StyleRuleList> m_styleRuleList;
   MatchResult m_result;
 };
 
 }  // namespace blink
 
 #endif  // ElementRuleCollector_h