Revert of Oilpan: Remove raw pointer to DescendantInvalidationSet from...

Revert of Oilpan: Remove raw pointer to DescendantInvalidationSet from StyleInvalidator::RecursionData (patchset #4 id:60001 of https://codereview.chromium.org/1225233005/ )

Reason for revert:
blink_perf.css regression
https://code.google.com/p/chromium/issues/detail?id=513378#makechanges

Original issue's description:
> Oilpan: Remove raw pointer to DescendantInvalidationSet from StyleInvalidator::RecursionData
> 
> BUG=509911
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=199288
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=199294

TBR=haraken@chromium.org,yutak@chromium.org,oilpan-reviews@chromium.org,sigbjornf@opera.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=509911

Review URL: https://codereview.chromium.org/1330763002

git-svn-id: svn://svn.chromium.org/blink/trunk@201869 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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

@@ -29,9 +29,7 @@ public:
     DECLARE_TRACE();
 
 private:
-    class RecursionData {
-        STACK_ALLOCATED();
-    public:
+    struct RecursionData {
         RecursionData()
             : m_invalidateCustomPseudo(false)
             , m_wholeSubtreeInvalid(false)
@@ -49,7 +47,7 @@ private:
         bool treeBoundaryCrossing() const { return m_treeBoundaryCrossing; }
         bool insertionPointCrossing() const { return m_insertionPointCrossing; }
 
-        using InvalidationSets = WillBeHeapVector<RawPtrWillBeMember<const DescendantInvalidationSet>, 16>;
+        using InvalidationSets = Vector<const DescendantInvalidationSet*, 16>;
         InvalidationSets m_invalidationSets;
         bool m_invalidateCustomPseudo;
         bool m_wholeSubtreeInvalid;
@@ -62,7 +60,6 @@ private:
     bool checkInvalidationSetsAgainstElement(Element&, RecursionData&);
 
     class RecursionCheckpoint {
-        STACK_ALLOCATED();
     public:
         RecursionCheckpoint(RecursionData* data)
             : m_prevInvalidationSetsSize(data->m_invalidationSets.size())
@@ -87,7 +84,6 @@ private:
         bool m_prevWholeSubtreeInvalid;
         bool m_treeBoundaryCrossing;
         bool m_insertionPointCrossing;
-        // This is a stack reference and need not separate tracing.
         RecursionData* m_data;
     };