Oilpan: disable conservative GCs during initial GC mixin construction.

Source/core/dom/Node.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004-2011, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.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
@@ skipping 95 matching lines @@
     NodeRareDataBase(LayoutObject* layoutObject)
         : m_layoutObject(layoutObject)
     { }
 
 protected:
     LayoutObject* m_layoutObject;
 };
 
 class Node;
 WILL_NOT_BE_EAGERLY_TRACED_CLASS(Node);
+WILL_HAVE_ALL_INSTANCES_ON_SAME_GC_HEAP(Node);
 
 #if ENABLE(OILPAN)
 #define NODE_BASE_CLASSES public EventTarget
 #else
 // TreeShared should be the last to pack TreeShared::m_refCount and
 // Node::m_nodeFlags on 64bit platforms.
 #define NODE_BASE_CLASSES public EventTarget, public TreeShared<Node>
 #endif
 
 class GC_PLUGIN_IGNORE("crbug.com/443854") Node : NODE_BASE_CLASSES {
@@ skipping 774 matching lines @@
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showNode(const blink::Node*);
 void showTree(const blink::Node*);
 void showNodePath(const blink::Node*);
 #endif
 
 #endif // Node_h