Replace RenderArena with PartitionAlloc.

Source/core/html/HTMLBRElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2003, 2006, 2009, 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 53 matching lines @@
         if (!value.isEmpty()) {
             if (equalIgnoringCase(value, "all"))
                 addPropertyToPresentationAttributeStyle(style, CSSPropertyClear, CSSValueBoth);
             else
                 addPropertyToPresentationAttributeStyle(style, CSSPropertyClear, value);
         }
     } else
         HTMLElement::collectStyleForPresentationAttribute(name, value, style);
 }
 
-RenderObject* HTMLBRElement::createRenderer(RenderArena* arena, RenderStyle* style)
+RenderObject* HTMLBRElement::createRenderer(RenderStyle* style)
 {
-     if (style->hasContent())
+    if (style->hasContent())
         return RenderObject::createObject(this, style);
 
-     return new (arena) RenderBR(this);
+    return new RenderBR(this);
 }
 
 }