Oilpan: Reduce FIXME(OILPAN) from the code base

Source/core/layout/svg/LayoutSVGResourceLinearGradient.h

 /*
  * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@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
  * 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 30 matching lines @@
     SVGUnitTypes::SVGUnitType gradientUnits() const override { return attributes().gradientUnits(); }
     void calculateGradientTransform(AffineTransform& transform) override { transform = attributes().gradientTransform(); }
     bool collectGradientAttributes(SVGGradientElement*) override;
     void buildGradient(GradientData*) const override;
 
     FloatPoint startPoint(const LinearGradientAttributes&) const;
     FloatPoint endPoint(const LinearGradientAttributes&) const;
 
 private:
 #if ENABLE(OILPAN)
-    // FIXME: Oilpan: the LayoutObject hierarchy isn't on the heap, but
-    // the SVG property hierarchy is. And the two meet here, so keep a
-    // persistent reference to the SVG part object by way of a heap-allocated
-    // wrapper object.
     Persistent<LinearGradientAttributesWrapper> m_attributesWrapper;
 
     LinearGradientAttributes& mutableAttributes() { return m_attributesWrapper->attributes(); }
     const LinearGradientAttributes& attributes() const { return m_attributesWrapper->attributes(); }
 #else
     LinearGradientAttributes m_attributes;
 
     LinearGradientAttributes& mutableAttributes() { return m_attributes; }
     const LinearGradientAttributes& attributes() const { return m_attributes; }
 #endif
 };
 
 } // namespace blink
 
 #endif // LayoutSVGResourceLinearGradient_h