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 15f087205287c8e6d9258c13149744eb81a00a9c..38e0b2278c9300e56b7436a500f63626f3f420a2 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -585,8 +585,10 @@ 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());