[binding] Check own property on named property accessor

Source/bindings/v8/custom/V8StyleSheetListCustom.cpp

Index: Source/bindings/v8/custom/V8StyleSheetListCustom.cpp
diff --git a/Source/bindings/v8/custom/V8StyleSheetListCustom.cpp b/Source/bindings/v8/custom/V8StyleSheetListCustom.cpp
index 90ba21797b54fbc31fa868cba3f5d2a45cfb9e3b..965d0f8c9f34c307537e4eed0dad47da59009ff1 100644
--- a/Source/bindings/v8/custom/V8StyleSheetListCustom.cpp
+++ b/Source/bindings/v8/custom/V8StyleSheetListCustom.cpp
@@ -40,6 +40,10 @@ namespace WebCore {
 
 v8::Handle<v8::Value> V8StyleSheetList::namedPropertyGetter(v8::Local<v8::String> name, const v8::AccessorInfo& info)
 {
+    if (!info.Holder()->GetRealNamedPropertyInPrototypeChain(name).IsEmpty())
+        return v8Undefined();
+    if (info.Holder()->HasRealNamedCallbackProperty(name))
+        return v8Undefined();
     if (info.Holder()->HasRealNamedProperty(name))
         return v8Undefined();