Implement callback reactions for Custom Elements V1

third_party/WebKit/Source/core/dom/custom/CustomElementReaction.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CustomElementReaction_h
 #define CustomElementReaction_h
 
 #include "core/CoreExport.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
+class CustomElementDefinition;
 class Element;
 
 class CORE_EXPORT CustomElementReaction
     : public GarbageCollectedFinalized<CustomElementReaction> {
     WTF_MAKE_NONCOPYABLE(CustomElementReaction);
 public:
-    CustomElementReaction() { }
-    virtual ~CustomElementReaction() { }
-    DEFINE_INLINE_VIRTUAL_TRACE() { }
+    CustomElementReaction(CustomElementDefinition*);
+    virtual ~CustomElementReaction() = default;
+
     virtual void invoke(Element*) = 0;
+
+    DECLARE_VIRTUAL_TRACE();
+
+protected:
+    Member<CustomElementDefinition> m_definition;
 };
 
 } // namespace blink
 
 #endif // CustomElementReaction_h