Have Node::document() return a reference instead of a pointer

Source/core/svg/SVGViewSpec.cpp

 /*
  * Copyright (C) 2007, 2010 Rob Buis <buis@kde.org>
  *
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 206 matching lines @@
         return false;
     ptr++;
 
     while (ptr < end && *ptr != ')') {
         if (*ptr == 'v') {
             if (skipString(ptr, end, viewBoxSpec, WTF_ARRAY_LENGTH(viewBoxSpec))) {
                 if (ptr >= end || *ptr != '(')
                     return false;
                 ptr++;
                 FloatRect viewBox;
-                if (!SVGFitToViewBox::parseViewBox(m_contextElement->document(), ptr, end, viewBox, false))
+                if (!SVGFitToViewBox::parseViewBox(&m_contextElement->document(), ptr, end, viewBox, false))
                     return false;
                 setViewBoxBaseValue(viewBox);
                 if (ptr >= end || *ptr != ')')
                     return false;
                 ptr++;
             } else if (skipString(ptr, end, viewTargetSpec, WTF_ARRAY_LENGTH(viewTargetSpec))) {
                 if (ptr >= end || *ptr != '(')
                     return false;
                 const CharType* viewTargetStart = ++ptr;
                 while (ptr < end && *ptr != ')')
@@ skipping 59 matching lines @@
         const LChar* ptr = spec.characters8();
         const LChar* end = ptr + spec.length();
         return parseViewSpecInternal(ptr, end);
     }
     const UChar* ptr = spec.characters16();
     const UChar* end = ptr + spec.length();
     return parseViewSpecInternal(ptr, end);
 }
 
 }