WIP (Introduce WTF::NonNullPtr<T>.)

Source/core/dom/LiveNodeList.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2008, 2010 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
  * version 2 of the License, or (at your option) any later version.
@@ skipping 55 matching lines @@
     const HTMLCollection* cacheBase = static_cast<const HTMLCollection*>(this);
     cacheBase->m_idCache.clear();
     cacheBase->m_nameCache.clear();
 }
 
 Node* LiveNodeList::namedItem(const AtomicString& elementId) const
 {
     Node* rootNode = this->rootNode();
 
     if (rootNode->inDocument()) {
-        Element* element = rootNode->treeScope().getElementById(elementId);
+        Element* element = rootNode->treeScope()->getElementById(elementId);
         if (element && nodeMatches(element) && element->isDescendantOf(rootNode))
             return element;
         if (!element)
             return 0;
         // In the case of multiple nodes with the same name, just fall through.
     }
 
     unsigned length = this->length();
     for (unsigned i = 0; i < length; i++) {
         Node* node = item(i);
         // FIXME: This should probably be using getIdAttribute instead of idForStyleResolution.
         if (node->hasID() && toElement(node)->idForStyleResolution() == elementId)
             return node;
     }
 
     return 0;
 }
 
 } // namespace WebCore