Use C++11 features in core/html

Source/core/html/HTMLTextFormControlElement.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, 2005, 2006, 2007 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * 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
@@ skipping 676 matching lines @@
 {
     ASSERT(position.isNull() || position.anchorType() == Position::PositionIsOffsetInAnchor
         || position.containerNode() || !position.anchorNode()->shadowHost()
         || (position.anchorNode()->parentNode() && position.anchorNode()->parentNode()->isShadowRoot()));
     return enclosingTextFormControl(position.containerNode());
 }
 
 HTMLTextFormControlElement* enclosingTextFormControl(Node* container)
 {
     if (!container)
-        return 0;
+        return nullptr;
     Element* ancestor = container->shadowHost();
     return ancestor && isHTMLTextFormControlElement(*ancestor) && container->containingShadowRoot()->type() == ShadowRoot::UserAgentShadowRoot ? toHTMLTextFormControlElement(ancestor) : 0;
 }
 
 String HTMLTextFormControlElement::directionForFormData() const
 {
     for (const HTMLElement* element = this; element; element = Traversal<HTMLElement>::firstAncestor(*element)) {
         const AtomicString& dirAttributeValue = element->fastGetAttribute(dirAttr);
         if (dirAttributeValue.isNull())
             continue;
@@ skipping 249 matching lines @@
             Text* textNode = toText(node);
             size_t firstLineBreak = textNode->data().find('\n', isPivotNode ? pivotPosition.offsetInContainerNode() : 0);
             if (firstLineBreak != kNotFound)
                 return Position(textNode, firstLineBreak + 1);
         }
     }
     return endOfInnerText(textFormControl);
 }
 
 } // namespace blink