Make sure the rootNode of a LiveNodeListBase is always a ContainerNode

Source/core/dom/EmptyNodeList.cpp

Index: Source/core/dom/EmptyNodeList.cpp
diff --git a/Source/core/dom/NodeRareData.cpp b/Source/core/dom/EmptyNodeList.cpp
similarity index 85%
copy from Source/core/dom/NodeRareData.cpp
copy to Source/core/dom/EmptyNodeList.cpp
index bbd863e8c68dd43aea889b838647899689b3a949..5f731886dccce6b77d27d759b90fe2f74d69bfbd 100644
--- a/Source/core/dom/NodeRareData.cpp
+++ b/Source/core/dom/EmptyNodeList.cpp
@@ -1,5 +1,6 @@
 /*
- * Copyright (C) 2012 Google Inc. All rights reserved.
+ * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2014 Samsung Electronics. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ -29,15 +30,16 @@
  */
 
 #include "config.h"
+#include "EmptyNodeList.h"
+
+#include "core/dom/Node.h"
 #include "core/dom/NodeRareData.h"
 
 namespace WebCore {
 
-struct SameSizeAsNodeRareData {
-    unsigned m_bitfields : 20;
-    void* m_pointer[3];
-};
-
-COMPILE_ASSERT(sizeof(NodeRareData) == sizeof(SameSizeAsNodeRareData), NodeRareDataShouldStaySmall);
+EmptyNodeList::~EmptyNodeList()
+{
+    m_owner->nodeLists()->removeEmptyChildNodeList(this);
+}
 
 } // namespace WebCore