Oilpan: DOM wrappers don't need to keep persistent handles

Source/bindings/core/v8/NPV8Object.cpp

 /*
  * Copyright (C) 2004, 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2007, 2008, 2009 Google, Inc.  All rights reserved.
  * Copyright (C) 2014 Opera Software ASA. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 32 matching lines @@
 #include "platform/UserGestureIndicator.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/StringExtras.h"
 #include "wtf/text/WTFString.h"
 #include <stdio.h>
 
 using namespace blink;
 
 namespace {
 
-WrapperPersistentNode* createPersistentHandle(ScriptWrappableBase* internalPointer)
+void trace(Visitor*, ScriptWrappableBase*)
 {
-    ASSERT_NOT_REACHED();
-    return 0;
 }
 
 } // namespace
 
 namespace blink {
 
 const WrapperTypeInfo* npObjectTypeInfo()
 {
-    static const WrapperTypeInfo typeInfo = { gin::kEmbedderBlink, 0, 0, 0, createPersistentHandle, 0, 0, 0, 0, 0, 0, WrapperTypeInfo::WrapperTypeObjectPrototype, WrapperTypeInfo::ObjectClassId, WrapperTypeInfo::Dependent, WrapperTypeInfo::RefCountedObject };
+    static const WrapperTypeInfo typeInfo = { gin::kEmbedderBlink, 0, 0, 0, trace, 0, 0, 0, 0, 0, 0, WrapperTypeInfo::WrapperTypeObjectPrototype, WrapperTypeInfo::ObjectClassId, WrapperTypeInfo::Dependent, WrapperTypeInfo::RefCountedObject };
     return &typeInfo;
 }
 
 // FIXME: Comments on why use malloc and free.
 static NPObject* allocV8NPObject(NPP, NPClass*)
 {
     return static_cast<NPObject*>(malloc(sizeof(V8NPObject)));
 }
 
 static void freeV8NPObject(NPObject* npObject)
@@ skipping 540 matching lines @@
 
         convertV8ObjectToNPVariant(resultObject, npObject, result, isolate);
         return true;
     }
 
     if (NP_CLASS_STRUCT_VERSION_HAS_CTOR(npObject->_class) && npObject->_class->construct)
         return npObject->_class->construct(npObject, arguments, argumentCount, result);
 
     return false;
 }