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

Source/core/dom/NodeTraversal.h

Index: Source/core/dom/NodeTraversal.h
diff --git a/Source/core/dom/NodeTraversal.h b/Source/core/dom/NodeTraversal.h
index b069dc5cd0605b8843ae367a8c950b81d65e6746..61c2c29d6425c4c4de38444978d3c94fe24ca83a 100644
--- a/Source/core/dom/NodeTraversal.h
+++ b/Source/core/dom/NodeTraversal.h
@@ -29,6 +29,7 @@
 #include "core/CoreExport.h"
 #include "core/dom/ContainerNode.h"
 #include "core/dom/Node.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
@@ -39,6 +40,7 @@ template <class TraversalNext> class TraversalInclusiveDescendantIterator;
 template <class TraversalNext> class TraversalNextIterator;
 
 class NodeTraversal {
+    STATIC_ONLY(NodeTraversal);
 public:
     using TraversalNodeType = Node;