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

Source/core/rendering/svg/RenderSVGResourceFilter.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
  * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2010. 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
@@ skipping 197 matching lines @@
         m_filter.set(object, filterData.leakPtr());
         return false;
     }
 
     // Change the coordinate transformation applied to the filtered element to reflect the resolution of the filter.
     AffineTransform effectiveTransform;
     effectiveTransform.scale(scale.width(), scale.height());
     effectiveTransform.multiply(filterData->shearFreeAbsoluteTransform);
 
     OwnPtr<ImageBuffer> sourceGraphic;
-    RenderingMode renderingMode = object->document()->page()->settings().acceleratedFiltersEnabled() ? Accelerated : Unaccelerated;
+    RenderingMode renderingMode = object->document().page()->settings().acceleratedFiltersEnabled() ? Accelerated : Unaccelerated;
     if (!SVGRenderingContext::createImageBuffer(filterData->drawingRegion, effectiveTransform, sourceGraphic, renderingMode)) {
         ASSERT(!m_filter.contains(object));
         filterData->savedContext = context;
         m_filter.set(object, filterData.leakPtr());
         return false;
     }
 
     // Set the rendering mode from the page's settings.
     filterData->filter->setRenderingMode(renderingMode);
 
@@ skipping 115 matching lines @@
     markAllClientLayersForInvalidation();
 }
 
 FloatRect RenderSVGResourceFilter::drawingRegion(RenderObject* object) const
 {
     FilterData* filterData = m_filter.get(object);
     return filterData ? filterData->drawingRegion : FloatRect();
 }
 
 }