Oilpan: Remove raw pointer to DescendantInvalidationSet from StyleInvalidator::RecursionData

Source/core/css/invalidation/StyleInvalidator.h

Index: Source/core/css/invalidation/StyleInvalidator.h
diff --git a/Source/core/css/invalidation/StyleInvalidator.h b/Source/core/css/invalidation/StyleInvalidator.h
index 440002260098e51a0748129c8d82599039d91aeb..82d93d8181ae9ec301e6ab27c6d943082d5847b7 100644
--- a/Source/core/css/invalidation/StyleInvalidator.h
+++ b/Source/core/css/invalidation/StyleInvalidator.h
@@ -29,7 +29,9 @@ public:
     DECLARE_TRACE();
 
 private:
-    struct RecursionData {
+    class RecursionData {
+        DISALLOW_ALLOCATION();
+    public:
         RecursionData()
             : m_invalidateCustomPseudo(false)
             , m_wholeSubtreeInvalid(false)
@@ -37,6 +39,13 @@ private:
             , m_insertionPointCrossing(false)
         { }
 
+        DEFINE_INLINE_TRACE()
+        {
+#if ENABLE(OILPAN)
+            visitor->trace(m_invalidationSets);
+#endif
+        }
+
         void pushInvalidationSet(const DescendantInvalidationSet&);
         bool matchesCurrentInvalidationSets(Element&);
         bool hasInvalidationSets() const { return !wholeSubtreeInvalid() && m_invalidationSets.size(); }
@@ -47,7 +56,7 @@ private:
         bool treeBoundaryCrossing() const { return m_treeBoundaryCrossing; }
         bool insertionPointCrossing() const { return m_insertionPointCrossing; }
 
-        using InvalidationSets = Vector<const DescendantInvalidationSet*, 16>;
+        using InvalidationSets = WillBeHeapVector<RawPtrWillBeMember<const DescendantInvalidationSet>, 16>;
         InvalidationSets m_invalidationSets;
         bool m_invalidateCustomPseudo;
         bool m_wholeSubtreeInvalid;