Remove custom element type extensions.

sky/engine/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 659 matching lines @@
         classAttributeChanged(newValue);
     }
 
     // If there is currently no StyleResolver, we can't be sure that this attribute change won't affect style.
     if (!styleResolver)
         setNeedsStyleRecalc(SubtreeStyleChange);
 }
 
 inline void Element::attributeChangedFromParserOrByCloning(const QualifiedName& name, const AtomicString& newValue, AttributeModificationReason reason)
 {
-    if (name == HTMLNames::isAttr)
-        CustomElementRegistrationContext::setTypeExtension(this, newValue);
     attributeChanged(name, newValue, reason);
 }
 
 template <typename CharacterType>
 static inline bool classStringHasClassName(const CharacterType* characters, unsigned length)
 {
     ASSERT(length > 0);
 
     unsigned i = 0;
     do {
@@ skipping 1131 matching lines @@
         return false;
     // Turn off style sharing for elements that can gain layers for reasons outside of the style system.
     // See comments in RenderObject::setStyle().
     // FIXME: Why does gaining a layer from outside the style system require disabling sharing?
     if (isHTMLCanvasElement(*this))
         return false;
     return true;
 }
 
 } // namespace blink