Have bindings layer assume and insist that all interface types are GCed.

third_party/WebKit/Source/bindings/core/v8/DOMDataStore.h

 /*
  * Copyright (C) 2009 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 197 matching lines @@
         ASSERT(wrappable);
         ASSERT(!wrappable->containsWrapper() || !wrappable->isEqualTo(holder) || current(v8::Isolate::GetCurrent()).m_isMainWorld);
         return wrappable->isEqualTo(holder);
     }
 
     bool m_isMainWorld;
     OwnPtr<DOMWrapperMap<ScriptWrappable>> m_wrapperMap;
 };
 
 template<>
-inline void DOMWrapperMap<ScriptWrappable>::PersistentValueMapTraits::Dispose(v8::Isolate*, v8::Global<v8::Object> value, ScriptWrappable* key)
+inline void DOMWrapperMap<ScriptWrappable>::PersistentValueMapTraits::Dispose(v8::Isolate*, v8::Global<v8::Object> value, ScriptWrappable*)
 {
-    auto wrapperTypeInfo = toWrapperTypeInfo(value);
-    if (wrapperTypeInfo->isGarbageCollected())
-        wrapperTypeInfo->derefObject();
-    else
-        wrapperTypeInfo->derefObject(toScriptWrappable(value));
+    toWrapperTypeInfo(value)->wrapperDestroyed();
 }
 
 template<>
 inline void DOMWrapperMap<ScriptWrappable>::PersistentValueMapTraits::DisposeWeak(const v8::WeakCallbackInfo<WeakCallbackDataType>& data)
 {
     auto wrapperTypeInfo = reinterpret_cast<WrapperTypeInfo*>(data.GetInternalField(v8DOMWrapperTypeIndex));
-    if (wrapperTypeInfo->isGarbageCollected())
-        wrapperTypeInfo->derefObject();
-    else
-        wrapperTypeInfo->derefObject(KeyFromWeakCallbackInfo(data));
+    wrapperTypeInfo->wrapperDestroyed();
 }
 
 } // namespace blink
 
 #endif // DOMDataStore_h