Remove ENABLE_CUSTOM_ELEMENTS compile time flag

Source/core/dom/Element.cpp

 /*
  * 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)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 859 matching lines @@
 
     if (shouldInvalidateStyle)
         setNeedsStyleRecalc();
 
     if (AXObjectCache* cache = document()->existingAXObjectCache())
         cache->handleAttributeChanged(name, this);
 }
 
 inline void Element::attributeChangedFromParserOrByCloning(const QualifiedName& name, const AtomicString& newValue, AttributeModificationReason reason)
 {
-#if ENABLE(CUSTOM_ELEMENTS)
     if (name == isAttr) {
         if (CustomElementRegistry* registry = document()->registry())
             registry->didGiveTypeExtension(this);
     }
-#endif
     attributeChanged(name, newValue, reason);
 }
 
 template <typename CharacterType>
 static inline bool classStringHasClassName(const CharacterType* characters, unsigned length)
 {
     ASSERT(length > 0);
 
     unsigned i = 0;
     do {
@@ skipping 2217 matching lines @@
     return 0;
 }
 
 Attribute* UniqueElementData::attributeItem(unsigned index)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(index < length());
     return &m_attributeVector.at(index);
 }
 
 } // namespace WebCore