Remove some useless null checks in Element/NamedNodeMap

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 17 matching lines @@
 #include "bindings/v8/ExceptionState.h"
 #include "core/dom/Attr.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/ExceptionCode.h"
 
 namespace WebCore {
 
 using namespace HTMLNames;
 
-static inline bool shouldIgnoreAttributeCase(const Element* e)
-{
-    return e && e->document().isHTMLDocument() && e->isHTMLElement();
-}
-
 void NamedNodeMap::ref()
 {
     m_element->ref();
 }
 
 void NamedNodeMap::deref()
 {
     m_element->deref();
 }
 
 PassRefPtr<Node> NamedNodeMap::getNamedItem(const AtomicString& name) const
 {
     return m_element->getAttributeNode(name);
 }
 
 PassRefPtr<Node> NamedNodeMap::getNamedItemNS(const AtomicString& namespaceURI, const AtomicString& localName) const
 {
     return m_element->getAttributeNodeNS(namespaceURI, localName);
 }
 
 PassRefPtr<Node> NamedNodeMap::removeNamedItem(const AtomicString& name, ExceptionState& es)
 {
-    size_t index = m_element->hasAttributes() ? m_element->getAttributeItemIndex(name, shouldIgnoreAttributeCase(m_element)) : kNotFound;
+    size_t index = m_element->hasAttributes() ? m_element->getAttributeItemIndex(name, m_element->shouldIgnoreAttributeCase()) : kNotFound;
     if (index == kNotFound) {
         es.throwUninformativeAndGenericDOMException(NotFoundError);
         return 0;
     }
     return m_element->detachAttribute(index);
 }
 
 PassRefPtr<Node> NamedNodeMap::removeNamedItemNS(const AtomicString& namespaceURI, const AtomicString& localName, ExceptionState& es)
 {
     size_t index = m_element->hasAttributes() ? m_element->getAttributeItemIndex(QualifiedName(nullAtom, localName, namespaceURI)) : kNotFound;
@@ skipping 33 matching lines @@
 }
 
 size_t NamedNodeMap::length() const
 {
     if (!m_element->hasAttributes())
         return 0;
     return m_element->attributeCount();
 }
 
 } // namespace WebCore