Backend for css rule tracking

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

Index: third_party/WebKit/Source/core/css/ElementRuleCollector.cpp
diff --git a/third_party/WebKit/Source/core/css/ElementRuleCollector.cpp b/third_party/WebKit/Source/core/css/ElementRuleCollector.cpp
index ef1bc2f4ee9c88cece4673713c6a9176823025c9..c77c0da1d62db403fadcb59e1dff9bc28c9c21cd 100644
--- a/third_party/WebKit/Source/core/css/ElementRuleCollector.cpp
+++ b/third_party/WebKit/Source/core/css/ElementRuleCollector.cpp
@@ -41,10 +41,10 @@
 #include "core/css/StylePropertySet.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/css/resolver/StyleResolverStats.h"
+#include "core/css/resolver/StyleRuleUsageTracker.h"
 #include "core/dom/StyleEngine.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/style/StyleInheritedData.h"
-#include <algorithm>
 
 namespace blink {
 
@@ -371,4 +371,10 @@ bool ElementRuleCollector::hasAnyMatchingRules(RuleSet* ruleSet) {
   return !m_matchedRules.isEmpty();
 }
 
+void ElementRuleCollector::addMatchedRulesToTracker(
+    StyleRuleUsageTracker* tracker) const {
+  for (auto matchedRule : m_matchedRules)
+    tracker->track(matchedRule.ruleData()->rule());
+}
+
 }  // namespace blink