Introduce infrastructure for tracing ScriptWrappables.

third_party/WebKit/Source/core/dom/Node.cpp

 /*
  * 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, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 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
@@ skipping 321 matching lines @@
     document.markers().removeMarkers(this);
 }
 #endif
 
 NodeRareData* Node::rareData() const
 {
     ASSERT_WITH_SECURITY_IMPLICATION(hasRareData());
     return static_cast<NodeRareData*>(m_data.m_rareData);
 }
 
+NodeRareData* Node::maybeRareData() const

[haraken, 2016/04/13 12:26:22]

maybeRareData => rareDataForTraceWrappers (to clarify this method is intended
only for traceWrappers)

[Marcel Hlopko, 2016/04/14 16:39:08]

Removed completely, I'll write traceWrappers for Node by hand (in order not to
introduce too many "useless" const getters). It was there to demonstrate how
interaction with non-scriptWrappable will look like, and I think it is clear now
:)

+{
+    return hasRareData() ? rareData() : nullptr;
+}
+
 NodeRareData& Node::ensureRareData()
 {
     if (hasRareData())
         return *rareData();
 
     if (isElementNode())
         m_data.m_rareData = ElementRareData::create(m_data.m_layoutObject);
     else
         m_data.m_rareData = NodeRareData::create(m_data.m_layoutObject);
 
@@ skipping 2116 matching lines @@
 
 void showNodePath(const blink::Node* node)
 {
     if (node)
         node->showNodePathForThis();
     else
         fprintf(stderr, "Cannot showNodePath for (nil)\n");
 }
 
 #endif