Move LayoutObject to satellite NodeLayoutData that hangs from a Node.

third_party/WebKit/Source/core/dom/NodeRareData.h

 /*
  * Copyright (C) 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Smith <catfish.man@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 80 matching lines @@
       transient_registry_;
 };
 
 DEFINE_TRAIT_FOR_TRACE_WRAPPERS(NodeMutationObserverData);
 
 class NodeRareData : public GarbageCollectedFinalized<NodeRareData>,
                      public NodeRareDataBase {
   WTF_MAKE_NONCOPYABLE(NodeRareData);
 
  public:
-  static NodeRareData* Create(LayoutObject* layout_object) {
-    return new NodeRareData(layout_object);
+  static NodeRareData* Create(NodeLayoutData* node_layout_data) {
+    return new NodeRareData(node_layout_data);
   }
 
   void ClearNodeLists() { node_lists_.Clear(); }
   NodeListsNodeData* NodeLists() const { return node_lists_.Get(); }
   // ensureNodeLists() and a following NodeListsNodeData functions must be
   // wrapped with a ThreadState::GCForbiddenScope in order to avoid an
   // initialized m_nodeLists is cleared by NodeRareData::traceAfterDispatch().
   NodeListsNodeData& EnsureNodeLists() {
     DCHECK(ThreadState::Current()->IsGCForbidden());
     if (!node_lists_) {
@@ skipping 43 matching lines @@
 
   DECLARE_TRACE();
 
   DECLARE_TRACE_AFTER_DISPATCH();
   void FinalizeGarbageCollectedObject();
 
   DECLARE_TRACE_WRAPPERS();
   DECLARE_TRACE_WRAPPERS_AFTER_DISPATCH();
 
  protected:
-  explicit NodeRareData(LayoutObject* layout_object)
-      : NodeRareDataBase(layout_object),
+  explicit NodeRareData(NodeLayoutData* node_layout_data)
+      : NodeRareDataBase(node_layout_data),
         connected_frame_count_(0),
         element_flags_(0),
         restyle_flags_(0),
-        is_element_rare_data_(false) {}
+        is_element_rare_data_(false) {
+    CHECK_NE(node_layout_data, nullptr);
+  }
 
  private:
   Member<NodeListsNodeData> node_lists_;
   Member<NodeMutationObserverData> mutation_observer_data_;
 
   unsigned connected_frame_count_ : kConnectedFrameCountBits;
   unsigned element_flags_ : kNumberOfElementFlags;
   unsigned restyle_flags_ : kNumberOfDynamicRestyleFlags;
 
  protected:
   unsigned is_element_rare_data_ : 1;
 };
 
 DEFINE_TRAIT_FOR_TRACE_WRAPPERS(NodeRareData);
 
 }  // namespace blink
 
 #endif  // NodeRareData_h