Free HashSets on setWholeSubtreeInvalid.

Source/core/css/analyzer/DescendantInvalidationSet.cpp

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 25 matching lines @@
 
 namespace WebCore {
 
 DescendantInvalidationSet::DescendantInvalidationSet()
     : m_allDescendantsMightBeInvalid(false)
 {
 }
 
 void DescendantInvalidationSet::combine(const DescendantInvalidationSet& other)
 {
-    m_allDescendantsMightBeInvalid = m_allDescendantsMightBeInvalid || other.m_allDescendantsMightBeInvalid;
     // No longer bother combining data structures, since the whole subtree is deemed invalid.
-    if (m_allDescendantsMightBeInvalid)
+    if (wholeSubtreeInvalid())
         return;
 
+    if (other.wholeSubtreeInvalid()) {
+        setWholeSubtreeInvalid();
+        return;
+    }
+
     if (other.m_classes) {
         HashSet<AtomicString>::const_iterator end = other.m_classes->end();
         for (HashSet<AtomicString>::const_iterator it = other.m_classes->begin(); it != end; ++it)
             addClass(*it);
     }
 
     if (other.m_ids) {
         HashSet<AtomicString>::const_iterator end = other.m_ids->end();
         for (HashSet<AtomicString>::const_iterator it = other.m_ids->begin(); it != end; ++it)
             addId(*it);
@@ skipping 22 matching lines @@
 
 HashSet<AtomicString>& DescendantInvalidationSet::ensureTagNameSet()
 {
     if (!m_tagNames)
         m_tagNames = adoptPtr(new HashSet<AtomicString>);
     return *m_tagNames;
 }
 
 void DescendantInvalidationSet::addClass(const AtomicString& className)
 {
+    if (wholeSubtreeInvalid())
+        return;
     ensureClassSet().add(className);
 }
 
 void DescendantInvalidationSet::addId(const AtomicString& id)
 {
+    if (wholeSubtreeInvalid())
+        return;
     ensureIdSet().add(id);
 }
 
 void DescendantInvalidationSet::addTagName(const AtomicString& tagName)
 {
+    if (wholeSubtreeInvalid())
+        return;
     ensureTagNameSet().add(tagName);
 }
 
-void DescendantInvalidationSet::getClasses(Vector<AtomicString>& classes)
+void DescendantInvalidationSet::getClasses(Vector<AtomicString>& classes) const
 {
     if (!m_classes)
         return;
     for (HashSet<AtomicString>::const_iterator it = m_classes->begin(); it != m_classes->end(); ++it)
         classes.append(*it);
 }
 
 } // namespace WebCore