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

Source/core/dom/DOMNodeIds.h

Index: Source/core/dom/DOMNodeIds.h
diff --git a/Source/core/dom/DOMNodeIds.h b/Source/core/dom/DOMNodeIds.h
index 8a05a54e561af7bda2783ed87902081c5d909cfa..52023a46245cf11edffd3698fa3a83dce2b9fccc 100644
--- a/Source/core/dom/DOMNodeIds.h
+++ b/Source/core/dom/DOMNodeIds.h
@@ -8,6 +8,7 @@
 #include "core/CoreExport.h"
 #include "core/dom/Node.h"
 #include "core/dom/WeakIdentifierMap.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
@@ -21,6 +22,7 @@ template<> struct WeakIdentifierMapTraits<Node> {
 DECLARE_WEAK_IDENTIFIER_MAP(Node);
 
 class CORE_EXPORT DOMNodeIds {
+    STATIC_ONLY(DOMNodeIds);
 public:
     static int idForNode(Node*);
     static Node* nodeForId(int id);