Backend for css rule tracking

third_party/WebKit/Source/core/css/resolver/StyleResolver.h

Index: third_party/WebKit/Source/core/css/resolver/StyleResolver.h
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleResolver.h b/third_party/WebKit/Source/core/css/resolver/StyleResolver.h
index 94056e8a1b0594d10ade163fc707d76dd1528197..fcac3552c42007d7a2728c116fa227368f7e0cd9 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleResolver.h
+++ b/third_party/WebKit/Source/core/css/resolver/StyleResolver.h
@@ -56,6 +56,7 @@ class MatchResult;
 class MediaQueryEvaluator;
 class StylePropertySet;
 class StyleRule;
+class StyleRuleUsageTracker;
 
 enum StyleSharingBehavior {
   AllowStyleSharing,
@@ -177,6 +178,8 @@ class CORE_EXPORT StyleResolver final
 
   DECLARE_TRACE();
 
+  void setRuleUsageTracker(StyleRuleUsageTracker*);
+
  private:
   explicit StyleResolver(Document&);
 
@@ -185,6 +188,8 @@ class CORE_EXPORT StyleResolver final
   // FIXME: This should probably go away, folded into FontBuilder.
   void updateFont(StyleResolverState&);
 
+  void addMatchedRulesToTracker(const ElementRuleCollector&);
+
   void loadPendingResources(StyleResolverState&);
   void adjustComputedStyle(StyleResolverState&, Element*);
 
@@ -288,6 +293,8 @@ class CORE_EXPORT StyleResolver final
 
   HeapListHashSet<Member<CSSStyleSheet>, 16> m_pendingStyleSheets;
 
+  Member<StyleRuleUsageTracker> m_tracker;
+
   bool m_printMediaType;
 
   unsigned m_styleSharingDepth;