C++11: Replace 0 with nullptr where applicable in layout code.

Source/core/layout/svg/LayoutSVGModelObject.h

 /*
  * Copyright (c) 2009, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 29 matching lines @@
 // but not all. (e.g. LayoutSVGForeignObject, LayoutSVGBlock) thus methods
 // required by SVG layoutObjects need to be declared on LayoutObject, but shared
 // logic can go in this class or in SVGLayoutSupport.
 
 class LayoutSVGModelObject : public LayoutObject {
 public:
     explicit LayoutSVGModelObject(SVGElement*);
 
     virtual bool isChildAllowed(LayoutObject*, const ComputedStyle&) const override;
 
-    virtual LayoutRect clippedOverflowRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = 0) const override;
+    virtual LayoutRect clippedOverflowRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = nullptr) const override;
 
     virtual FloatRect paintInvalidationRectInLocalCoordinates() const override final { return m_paintInvalidationBoundingBox; }
 
     virtual void absoluteRects(Vector<IntRect>&, const LayoutPoint& accumulatedOffset) const override final;
     virtual void absoluteQuads(Vector<FloatQuad>&, bool* wasFixed) const override;
 
-    virtual void mapLocalToContainer(const LayoutBoxModelObject* paintInvalidationContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = 0, const PaintInvalidationState* = 0) const override final;
+    virtual void mapLocalToContainer(const LayoutBoxModelObject* paintInvalidationContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = nullptr, const PaintInvalidationState* = nullptr) const override final;
     virtual const LayoutObject* pushMappingToContainer(const LayoutBoxModelObject* ancestorToStopAt, LayoutGeometryMap&) const override final;
     virtual void styleDidChange(StyleDifference, const ComputedStyle* oldStyle) override;
 
     virtual void computeLayerHitTestRects(LayerHitTestRects&) const override final;
 
     SVGElement* element() const { return toSVGElement(LayoutObject::node()); }
 
     virtual bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectSVG || LayoutObject::isOfType(type); }
 
 protected:
@@ skipping 10 matching lines @@
 
     virtual void invalidateTreeIfNeeded(PaintInvalidationState&) override final;
 
 protected:
     FloatRect m_paintInvalidationBoundingBox;
 };
 
 }
 
 #endif