Oilpan: move node/element rare data objects to the heap.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index ac26f1f895f217552979672df40d5784e34a3ba0..84927cef6f747effa6696aa299036dda3bd65748 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -591,8 +591,10 @@ Document::~Document()
 
     // We must call clearRareData() here since a Document class inherits TreeScope
     // as well as Node. See a comment on TreeScope.h for the reason.
+#if !ENABLE(OILPAN)
     if (hasRareData())
         clearRareData();
+#endif
 
     ASSERT(!m_listsInvalidatedAtDocument.size());