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

Source/core/rendering/svg/RenderSVGInlineText.cpp

 /*
  * Copyright (C) 2006 Oliver Hunt <ojh16@student.canterbury.ac.nz>
  * Copyright (C) 2006 Apple Computer Inc.
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2008 Rob Buis <buis@kde.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 201 matching lines @@
 void RenderSVGInlineText::updateScaledFont()
 {
     computeNewScaledFontForStyle(this, style(), m_scalingFactor, m_scaledFont);
 }
 
 void RenderSVGInlineText::computeNewScaledFontForStyle(RenderObject* renderer, const RenderStyle* style, float& scalingFactor, Font& scaledFont)
 {
     ASSERT(style);
     ASSERT(renderer);
 
-    Document* document = renderer->document();
-    ASSERT(document);
+    Document& document = renderer->document();
 
-    StyleResolver* styleResolver = document->styleResolver();
+    StyleResolver* styleResolver = document.styleResolver();
     ASSERT(styleResolver);
 
     // Alter font-size to the right on-screen value to avoid scaling the glyphs themselves, except when GeometricPrecision is specified.
     scalingFactor = SVGRenderingContext::calculateScreenFontSizeScalingFactor(renderer);
     if (scalingFactor == 1 || !scalingFactor) {
         scalingFactor = 1;
         scaledFont = style->font();
         return;
     }
 
     if (style->fontDescription().textRenderingMode() == GeometricPrecision)
         scalingFactor = 1;
 
     FontDescription fontDescription(style->fontDescription());
 
     // FIXME: We need to better handle the case when we compute very small fonts below (below 1pt).
-    fontDescription.setComputedSize(FontSize::getComputedSizeFromSpecifiedSize(document, scalingFactor, fontDescription.isAbsoluteSize(), fontDescription.specifiedSize(), DoNotUseSmartMinimumForFontSize));
+    fontDescription.setComputedSize(FontSize::getComputedSizeFromSpecifiedSize(&document, scalingFactor, fontDescription.isAbsoluteSize(), fontDescription.specifiedSize(), DoNotUseSmartMinimumForFontSize));
 
     scaledFont = Font(fontDescription, 0, 0);
     scaledFont.update(styleResolver->fontSelector());
 }
 
 }