This CL clean up patch in SVGElements.

Source/core/svg/graphics/SVGImage.cpp

 /*
  * Copyright (C) 2006 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 110 matching lines @@
     }
 
     // Because SVG image rendering disallows external resources and links, these
     // images effectively are restricted to a single security origin.
     return true;
 }
 
 static SVGSVGElement* svgRootElement(Page* page)
 {
     if (!page)
-        return 0;
+        return nullptr;
     LocalFrame* frame = toLocalFrame(page->mainFrame());
     return frame->document()->accessSVGExtensions().rootElement();
 }
 
 void SVGImage::setContainerSize(const IntSize& size)
 {
     if (!usesContainerSize())
         return;
 
     SVGSVGElement* rootElement = svgRootElement(m_page.get());
@@ skipping 180 matching lines @@
     // Start any (SMIL) animations if needed. This will restart or continue
     // animations if preceded by calls to resetAnimation or stopAnimation
     // respectively.
     startAnimation();
 }
 
 LayoutBox* SVGImage::embeddedContentBox() const
 {
     SVGSVGElement* rootElement = svgRootElement(m_page.get());
     if (!rootElement)
-        return 0;
+        return nullptr;
     return toLayoutBox(rootElement->layoutObject());
 }
 
 FrameView* SVGImage::frameView() const
 {
     if (!m_page)
-        return 0;
+        return nullptr;
 
     return toLocalFrame(m_page->mainFrame())->view();
 }
 
 void SVGImage::computeIntrinsicDimensions(Length& intrinsicWidth, Length& intrinsicHeight, FloatSize& intrinsicRatio)
 {
     SVGSVGElement* rootElement = svgRootElement(m_page.get());
     if (!rootElement)
         return;
 
@@ skipping 109 matching lines @@
 
     return m_page;
 }
 
 String SVGImage::filenameExtension() const
 {
     return "svg";
 }
 
 }