Pass null to attributeChangedCallback when there's no namespace URI

third_party/WebKit/Source/bindings/core/v8/ScriptCustomElementDefinition.cpp

 // 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.
 
 #include "bindings/core/v8/ScriptCustomElementDefinition.h"
 
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "bindings/core/v8/V8BindingMacros.h"
 #include "bindings/core/v8/V8CustomElementRegistry.h"
@@ skipping 360 matching lines @@
 {
     if (!m_scriptState->contextIsValid())
         return;
     ScriptState::Scope scope(m_scriptState.get());
     v8::Isolate* isolate = m_scriptState->isolate();
     const int argc = 4;
     v8::Local<v8::Value> argv[argc] = {
         v8String(isolate, name.localName()),
         v8StringOrNull(isolate, oldValue),
         v8StringOrNull(isolate, newValue),
-        v8String(isolate, name.namespaceURI()),
+        v8StringOrNull(isolate, name.namespaceURI()),
     };
     runCallback(m_attributeChangedCallback.newLocal(isolate), element,
         argc, argv);
 }
 
 } // namespace blink