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

Source/core/dom/custom/CustomElementUpgradeCandidateMap.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 23 matching lines @@
 #include "core/dom/custom/CustomElementDescriptor.h"
 #include "core/dom/custom/CustomElementDescriptorHash.h"
 #include "core/dom/custom/CustomElementObserver.h"
 #include "wtf/HashMap.h"
 #include "wtf/LinkedHashSet.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
 class CustomElementUpgradeCandidateMap final : public CustomElementObserver {
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED(CustomElementUpgradeCandidateMap);
     WTF_MAKE_NONCOPYABLE(CustomElementUpgradeCandidateMap);
 public:
     static PassOwnPtrWillBeRawPtr<CustomElementUpgradeCandidateMap> create();
     ~CustomElementUpgradeCandidateMap() override;
 
     // API for CustomElementRegistrationContext to save and take candidates
 
     typedef WillBeHeapLinkedHashSet<RawPtrWillBeWeakMember<Element>> ElementSet;
 
     void add(const CustomElementDescriptor&, Element*);
     PassOwnPtrWillBeRawPtr<ElementSet> takeUpgradeCandidatesFor(const CustomElementDescriptor&);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     CustomElementUpgradeCandidateMap() { }
 
     void elementWasDestroyed(Element*) override;
 
     typedef WillBeHeapHashMap<RawPtrWillBeWeakMember<Element>, CustomElementDescriptor> UpgradeCandidateMap;
     UpgradeCandidateMap m_upgradeCandidates;
 
     typedef WillBeHeapHashMap<CustomElementDescriptor, OwnPtrWillBeMember<ElementSet>> UnresolvedDefinitionMap;
     UnresolvedDefinitionMap m_unresolvedDefinitions;
 };
 
 } // namespace blink
 
 #endif // CustomElementUpgradeCandidateMap_h