Move HTMLLabelElement-related complexity out of Element

Source/core/dom/Element.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2013 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 578 matching lines @@
     void didAddAttribute(const QualifiedName&, const AtomicString&);
     void willModifyAttribute(const QualifiedName&, const AtomicString& oldValue, const AtomicString& newValue);
     void didModifyAttribute(const QualifiedName&, const AtomicString&);
     void didRemoveAttribute(const QualifiedName&);
 
     void synchronizeAttribute(const QualifiedName&) const;
 
     void updateId(const AtomicString& oldId, const AtomicString& newId);
     void updateId(TreeScope&, const AtomicString& oldId, const AtomicString& newId);
     void updateName(const AtomicString& oldName, const AtomicString& newName);
-    void updateLabel(TreeScope&, const AtomicString& oldForAttributeValue, const AtomicString& newForAttributeValue);
 
     void scrollByUnits(int units, ScrollGranularity);
 
     virtual NodeType nodeType() const OVERRIDE FINAL;
     virtual bool childTypeAllowed(NodeType) const OVERRIDE FINAL;
 
     void setAttributeInternal(size_t index, const QualifiedName&, const AtomicString& value, SynchronizationOfLazyAttribute);
     void appendAttributeInternal(const QualifiedName&, const AtomicString& value, SynchronizationOfLazyAttribute);
     void removeAttributeInternal(size_t index, SynchronizationOfLazyAttribute);
     void attributeChangedFromParserOrByCloning(const QualifiedName&, const AtomicString&, AttributeModificationReason);
@@ skipping 259 matching lines @@
     static PassRefPtrWillBeRawPtr<T> create(const QualifiedName&, Document&)
 #define DEFINE_ELEMENT_FACTORY_WITH_TAGNAME(T) \
     PassRefPtrWillBeRawPtr<T> T::create(const QualifiedName& tagName, Document& document) \
     { \
         return adoptRefWillBeNoop(new T(tagName, document)); \
     }
 
 } // namespace
 
 #endif