Remove attributeCount() / attributeAt() API from Element

Source/core/dom/NamedNodeMap.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)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 81 matching lines @@
     return m_element->setAttributeNode(toAttr(node), exceptionState);
 }
 
 PassRefPtrWillBeRawPtr<Node> NamedNodeMap::setNamedItemNS(Node* node, ExceptionState& exceptionState)
 {
     return setNamedItem(node, exceptionState);
 }
 
 PassRefPtrWillBeRawPtr<Node> NamedNodeMap::item(unsigned index) const
 {
-    if (index >= length())
+    if (!m_element->hasAttributes())
         return nullptr;
-    return m_element->ensureAttr(m_element->attributeAt(index).name());
+    AttributeCollection attributes = m_element->attributes();
+    if (index >= attributes.size())
+        return nullptr;
+    return m_element->ensureAttr(attributes[index].name());
 }
 
 size_t NamedNodeMap::length() const
 {
     if (!m_element->hasAttributes())
         return 0;
-    return m_element->attributeCount();
+    return m_element->attributes().size();
 }
 
 void NamedNodeMap::trace(Visitor* visitor)
 {
     visitor->trace(m_element);
 }
 
 } // namespace WebCore