Oilpan: Make the Node hierarchy RefCountedGarbageCollected instead of TreeShared.

Source/core/dom/ContainerNode.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, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * 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.
@@ skipping 172 matching lines @@
 
     // -----------------------------------------------------------------------------
     // Notification of document structure changes (see core/dom/Node.h for more notification methods)
 
     // Notifies the node that it's list of children have changed (either by adding or removing child nodes), or a child
     // node that is of the type CDATA_SECTION_NODE, TEXT_NODE or COMMENT_NODE has changed its value.
     virtual void childrenChanged(bool createdByParser = false, Node* beforeChange = 0, Node* afterChange = 0, int childCountDelta = 0);
 
     void disconnectDescendantFrames();
 
+    virtual void trace(Visitor*) OVERRIDE;
+
 protected:
     ContainerNode(TreeScope*, ConstructionType = CreateContainer);
 
     template<class GenericNode, class GenericNodeContainer>
     friend void appendChildToContainer(GenericNode& child, GenericNodeContainer&);
 
     template<class GenericNode, class GenericNodeContainer>
     friend void Private::addChildNodesToDeletionQueue(GenericNode*& head, GenericNode*& tail, GenericNodeContainer&);
 
+#if !ENABLE(OILPAN)
     void removeDetachedChildren();
+#endif
+
     void setFirstChild(Node* child) { m_firstChild = child; }
     void setLastChild(Node* child) { m_lastChild = child; }
 
 private:
     void removeBetween(Node* previousChild, Node* nextChild, Node& oldChild);
     void insertBeforeCommon(Node& nextChild, Node& oldChild);
     void updateTreeAfterInsertion(Node& child);
     void willRemoveChildren();
     void willRemoveChild(Node& child);
 
     bool hasRestyleFlag(DynamicRestyleFlags mask) const { return hasRareData() && hasRestyleFlagInternal(mask); }
     bool hasRestyleFlags() const { return hasRareData() && hasRestyleFlagsInternal(); }
     void setRestyleFlag(DynamicRestyleFlags);
     bool hasRestyleFlagInternal(DynamicRestyleFlags) const;
     bool hasRestyleFlagsInternal() const;
 
     inline bool checkAcceptChildGuaranteedNodeTypes(const Node& newChild, ExceptionState&) const;
     inline bool checkAcceptChild(const Node* newChild, const Node* oldChild, ExceptionState&) const;
     inline bool containsConsideringHostElements(const Node&) const;
     inline bool isChildTypeAllowed(const Node& child) const;
 
     void attachChildren(const AttachContext& = AttachContext());
     void detachChildren(const AttachContext& = AttachContext());
 
     bool getUpperLeftCorner(FloatPoint&) const;
     bool getLowerRightCorner(FloatPoint&) const;
 
-    Node* m_firstChild;
-    Node* m_lastChild;
+    RawPtrWillBeMember<Node> m_firstChild;
+    RawPtrWillBeMember<Node> m_lastChild;
 };
 
 #ifndef NDEBUG
 bool childAttachedAllowedWhenAttachingChildren(ContainerNode*);
 #endif
 
 DEFINE_NODE_TYPE_CASTS(ContainerNode, isContainerNode());
 
 inline bool ContainerNode::hasChildCount(unsigned count) const
 {
     Node* child = m_firstChild;
     while (count && child) {
         child = child->nextSibling();
         --count;
     }
     return !count && !child;
 }
 
 inline ContainerNode::ContainerNode(TreeScope* treeScope, ConstructionType type)
     : Node(treeScope, type)
-    , m_firstChild(0)
-    , m_lastChild(0)
+    , m_firstChild(nullptr)
+    , m_lastChild(nullptr)
 {
 }
 
 inline void ContainerNode::attachChildren(const AttachContext& context)
 {
     AttachContext childrenContext(context);
     childrenContext.resolvedStyle = 0;
 
     for (Node* child = firstChild(); child; child = child->nextSibling()) {
         ASSERT(child->needsAttach() || childAttachedAllowedWhenAttachingChildren(this));
@@ skipping 128 matching lines @@
 
     RefPtr<Node> m_currentNode;
     unsigned m_currentIndex;
     OwnPtr<Vector<RefPtr<Node> > > m_childNodes; // Lazily instantiated.
     ChildNodesLazySnapshot* m_nextSnapshot;
 };
 
 } // namespace WebCore
 
 #endif // ContainerNode_h