RuleSet invalidations on single feature only, including tags.

third_party/WebKit/Source/core/css/invalidation/InvalidationSet.cpp

Index: third_party/WebKit/Source/core/css/invalidation/InvalidationSet.cpp
diff --git a/third_party/WebKit/Source/core/css/invalidation/InvalidationSet.cpp b/third_party/WebKit/Source/core/css/invalidation/InvalidationSet.cpp
index c9831e7b8655e138cef09a260b1a16f539d6d6a7..2aa388843320e51da4f5556c7d704a7cdd14e1bb 100644
--- a/third_party/WebKit/Source/core/css/invalidation/InvalidationSet.cpp
+++ b/third_party/WebKit/Source/core/css/invalidation/InvalidationSet.cpp
@@ -62,7 +62,8 @@ InvalidationSet::InvalidationSet(InvalidationType type)
       m_customPseudoInvalid(false),
       m_treeBoundaryCrossing(false),
       m_insertionPointCrossing(false),
-      m_invalidatesSlotted(false) {}
+      m_invalidatesSlotted(false),
+      m_appliesToRuleSetInvalidations(false) {}
 
 bool InvalidationSet::invalidatesElement(Element& element) const {
   if (m_allDescendantsMightBeInvalid)
@@ -149,6 +150,9 @@ void InvalidationSet::combine(const InvalidationSet& other) {
   if (other.invalidatesSlotted())
     setInvalidatesSlotted();
 
+  if (other.appliesToRuleSetInvalidations())
+    setAppliesToRuleSetInvalidations();
+
   if (other.m_classes) {
     for (const auto& className : *other.m_classes)
       addClass(className);
@@ -259,6 +263,8 @@ void InvalidationSet::toTracedValue(TracedValue* value) const {
     value->setBoolean("insertionPointCrossing", true);
   if (m_invalidatesSlotted)
     value->setBoolean("invalidatesSlotted", true);
+  if (m_appliesToRuleSetInvalidations)
+    value->setBoolean("appliesToRuleSetInvalidations", true);
 
   if (m_ids) {
     value->beginArray("ids");