Make classes and structures in core/dom fast-allocated.

Source/core/dom/NodeTraversal.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, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2014 Samsung Electronics. 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
@@ skipping 11 matching lines @@
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef NodeTraversal_h
 #define NodeTraversal_h
 
 #include "core/CoreExport.h"
 #include "core/dom/ContainerNode.h"
 #include "core/dom/Node.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
 template <class Iterator> class TraversalRange;
 template <class TraversalNext> class TraversalChildrenIterator;
 template <class TraversalNext> class TraversalDescendantIterator;
 template <class TraversalNext> class TraversalInclusiveDescendantIterator;
 template <class TraversalNext> class TraversalNextIterator;
 
 class NodeTraversal {
+    STATIC_ONLY(NodeTraversal);
 public:
     using TraversalNodeType = Node;
 
     // Does a pre-order traversal of the tree to find the next node after this one.
     // This uses the same order that tags appear in the source file. If the stayWithin
     // argument is non-null, the traversal will stop once the specified node is reached.
     // This can be used to restrict traversal to a particular sub-tree.
     static Node* next(const Node& current) { return traverseNextTemplate(current); }
     static Node* next(const ContainerNode& current) { return traverseNextTemplate(current); }
     static Node* next(const Node& current, const Node* stayWithin) { return traverseNextTemplate(current, stayWithin); }
@@ skipping 214 matching lines @@
 {
     Node* child = parent.firstChild();
     while (child && index--)
         child = child->nextSibling();
     return child;
 }
 
 } // namespace blink
 
 #endif