This CL clean up patch in SVGElements.

Source/core/svg/SVGLengthContext.cpp

 /*
  * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. 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.
@@ skipping 38 matching lines @@
 }
 
 static float convertValueFromPercentageToUserUnits(const SVGLength& value, const FloatSize& viewportSize)
 {
     return CSSPrimitiveValue::clampToCSSLengthRange(value.scaleByPercentage(dimensionForLengthMode(value.unitMode(), viewportSize)));
 }
 
 static const ComputedStyle* computedStyleForLengthResolving(const SVGElement* context)
 {
     if (!context)
-        return 0;
+        return nullptr;
 
     const ContainerNode* currentContext = context;
     do {
         if (currentContext->layoutObject())
             return currentContext->layoutObject()->style();
         currentContext = currentContext->parentNode();
     } while (currentContext);
 
     // There must be at least a LayoutSVGRoot layoutObject, carrying a style.
     ASSERT_NOT_REACHED();
-    return 0;
+    return nullptr;
 }
 
 static const ComputedStyle* rootElementStyle(const Node* context)
 {
     if (!context)
-        return 0;
+        return nullptr;
 
     const Document& document = context->document();
     Node* documentElement = document.documentElement();
     const ComputedStyle* documentStyle = document.computedStyle();
     const ComputedStyle* style = documentElement && context != documentElement ? documentElement->computedStyle() : documentStyle;
     if (!style)
         style = documentStyle;
     return style;
 }
 
@@ skipping 258 matching lines @@
 
     const SVGSVGElement& svg = toSVGSVGElement(*viewportElement);
     viewportSize = svg.currentViewBoxRect().size();
     if (viewportSize.isEmpty())
         viewportSize = svg.currentViewportSize();
 
     return true;
 }
 
 }