Creating custom element should not be case sensitive

Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 1029 matching lines @@
     void registerVisibilityObserver(DocumentVisibilityObserver*);
     void unregisterVisibilityObserver(DocumentVisibilityObserver*);
 
     void updateStyleInvalidationIfNeeded();
 
     virtual void trace(Visitor*) OVERRIDE;
 
     bool hasSVGFilterElementsRequiringLayerUpdate() const { return m_layerUpdateSVGFilterElements.size(); }
     void didRecalculateStyleForElement() { ++m_styleRecalcElementCounter; }
 
+    AtomicString convertLocalName(const AtomicString&);
+
 protected:
     Document(const DocumentInit&, DocumentClassFlags = DefaultDocumentClass);
 
     virtual void didUpdateSecurityOrigin() OVERRIDE FINAL;
 
     void clearXMLVersion() { m_xmlVersion = String(); }
 
 #if !ENABLE(OILPAN)
     virtual void dispose() OVERRIDE;
 #endif
@@ skipping 361 matching lines @@
 Node* eventTargetNodeForDocument(Document*);
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLiveDocumentInstances();
 #endif
 
 #endif // Document_h