V8 Binding: Introduce toNativeWithTypeCheck

Source/bindings/v8/custom/V8ArrayBufferCustom.cpp

 /*
  * 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 76 matching lines @@
     ArrayBufferContents contents(v8Contents.Data(), v8Contents.ByteLength(),
         V8ArrayBufferDeallocationObserver::instanceTemplate());
     RefPtr<ArrayBuffer> buffer = ArrayBuffer::create(contents);
     V8DOMWrapper::associateObjectWithWrapper<V8ArrayBuffer>(buffer.release(), &wrapperTypeInfo, object, v8::Isolate::GetCurrent(), WrapperConfiguration::Dependent);
 
     arraybufferPtr = object->GetAlignedPointerFromInternalField(v8DOMWrapperObjectIndex);
     ASSERT(arraybufferPtr);
     return reinterpret_cast<ArrayBuffer*>(arraybufferPtr);
 }
 
+ArrayBuffer* V8ArrayBuffer::toNativeWithTypeCheck(v8::Isolate* isolate, v8::Handle<v8::Value> value)
+{
+    return V8ArrayBuffer::hasInstance(value, isolate) ? V8ArrayBuffer::toNative(v8::Handle<v8::Object>::Cast(value)) : 0;
+}
+
 template<>
 v8::Handle<v8::Value> toV8NoInline(ArrayBuffer* impl, v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
 {
     return toV8(impl, creationContext, isolate);
 }
 
 } // namespace WebCore