RuleSet invalidations on single feature only, including tags.

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

Index: third_party/WebKit/Source/core/css/invalidation/InvalidationSet.h
diff --git a/third_party/WebKit/Source/core/css/invalidation/InvalidationSet.h b/third_party/WebKit/Source/core/css/invalidation/InvalidationSet.h
index e6f0d3524039463876be9cf52f278d1773f8c78c..eb94702c8c0aabaaecf67333781e7ccf6f0ad25a 100644
--- a/third_party/WebKit/Source/core/css/invalidation/InvalidationSet.h
+++ b/third_party/WebKit/Source/core/css/invalidation/InvalidationSet.h
@@ -121,6 +121,13 @@ class CORE_EXPORT InvalidationSet {
   void setInvalidatesSlotted() { m_invalidatesSlotted = true; }
   bool invalidatesSlotted() const { return m_invalidatesSlotted; }
 
+  void setAppliesToRuleSetInvalidations() {
+    m_appliesToRuleSetInvalidations = true;
+  }
+  bool appliesToRuleSetInvalidations() const {
+    return m_appliesToRuleSetInvalidations;
+  }
+
   bool isEmpty() const {
     return !m_classes && !m_ids && !m_tagNames && !m_attributes &&
            !m_customPseudoInvalid && !m_insertionPointCrossing &&
@@ -205,6 +212,10 @@ class CORE_EXPORT InvalidationSet {
 
   // If true, distributed nodes of <slot> elements need to be invalidated.
   unsigned m_invalidatesSlotted : 1;
+
+  // If true, this invalidation set should be scheduled for ruleset
+  // invalidations.
+  unsigned m_appliesToRuleSetInvalidations : 1;
 };
 
 class CORE_EXPORT DescendantInvalidationSet final : public InvalidationSet {
@@ -215,6 +226,8 @@ class CORE_EXPORT DescendantInvalidationSet final : public InvalidationSet {
 
  private:
   DescendantInvalidationSet() : InvalidationSet(InvalidateDescendants) {}
+  static PassRefPtr<DescendantInvalidationSet>
+  createCustomPseudoInvalidationSet();
 };
 
 class CORE_EXPORT SiblingInvalidationSet final : public InvalidationSet {