Make SVGLength store a const CSSValue

third_party/WebKit/Source/core/svg/SVGLength.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006 Rob Buis <buis@kde.org>
  *
  * 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 45 matching lines @@
 
     float value(const SVGLengthContext&) const;
     void setValue(float, const SVGLengthContext&);
 
     float valueInSpecifiedUnits() const { return m_value->getFloatValue(); }
     void setValueInSpecifiedUnits(float value)
     {
         m_value = CSSPrimitiveValue::create(value, m_value->typeWithCalcResolved());
     }
 
-    CSSPrimitiveValue* asCSSPrimitiveValue() const { return m_value.get(); }
+    const CSSPrimitiveValue* asCSSPrimitiveValue() const { return m_value.get(); }
 
     // Resolves LengthTypePercentage into a normalized floating point number (full value is 1.0).
     float valueAsPercentage() const;
 
     // Returns a number to be used as percentage (so full value is 100)
     float valueAsPercentage100() const;
 
     // Scale the input value by this SVGLength. Higher precision than input * valueAsPercentage().
     float scaleByPercentage(float) const;
 
@@ skipping 18 matching lines @@
     void calculateAnimatedValue(SVGAnimationElement*, float percentage, unsigned repeatCount, SVGPropertyBase* from, SVGPropertyBase* to, SVGPropertyBase* toAtEndOfDurationValue, SVGElement* contextElement) override;
     float calculateDistance(SVGPropertyBase* to, SVGElement* contextElement) override;
 
     static AnimatedPropertyType classType() { return AnimatedLength; }
     AnimatedPropertyType type() const override { return classType(); }
 
 private:
     SVGLength(SVGLengthMode);
     SVGLength(const SVGLength&);
 
-    Member<CSSPrimitiveValue> m_value;
+    Member<const CSSPrimitiveValue> m_value;
     unsigned m_unitMode : 2;
 };
 
 DEFINE_SVG_PROPERTY_TYPE_CASTS(SVGLength);
 
 } // namespace blink
 
 #endif // SVGLength_h