Have Document::accessSVGExtensions() return a reference

Source/core/rendering/RenderView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 208 matching lines @@
                 continue;
 
             if ((child->isBox() && toRenderBox(child)->hasRelativeLogicalHeight())
                     || child->style()->logicalHeight().isPercent()
                     || child->style()->logicalMinHeight().isPercent()
                     || child->style()->logicalMaxHeight().isPercent())
                 layoutScope.setChildNeedsLayout(child);
         }
 
         if (document().svgExtensions())
-            document().accessSVGExtensions()->invalidateSVGRootsWithRelativeLengthDescendents(&layoutScope);
+            document().accessSVGExtensions().invalidateSVGRootsWithRelativeLengthDescendents(&layoutScope);
     }
 
     ASSERT(!m_layoutState);
     if (!needsLayout())
         return;
 
     LayoutState state;
     initializeLayoutState(state);
 
     m_pageLogicalHeightChanged = false;
@@ skipping 767 matching lines @@
     return viewWidth(IncludeScrollbars) / scale;
 }
 
 double RenderView::layoutViewportHeight() const
 {
     float scale = m_frameView ? m_frameView->frame().pageZoomFactor() : 1;
     return viewHeight(IncludeScrollbars) / scale;
 }
 
 } // namespace WebCore