[SVG] SVGLength{,List} migration to new SVG property impl.

Source/core/svg/properties/NewSVGProperty.h

 /*
  * Copyright (C) 2013 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 48 matching lines @@
     virtual void add(PassRefPtr<NewSVGPropertyBase>, SVGElement*) = 0;
     virtual void calculateAnimatedValue(SVGAnimationElement*, float percentage, unsigned repeatCount, PassRefPtr<NewSVGPropertyBase> from, PassRefPtr<NewSVGPropertyBase> to, PassRefPtr<NewSVGPropertyBase> toAtEndOfDurationValue, SVGElement*) = 0;
     virtual float calculateDistance(PassRefPtr<NewSVGPropertyBase> to, SVGElement*) = 0;
 
     AnimatedPropertyType type()
     {
         return m_type;
     }
 
 protected:
-    NewSVGPropertyBase(AnimatedPropertyType type)
+    explicit NewSVGPropertyBase(AnimatedPropertyType type)
         : m_type(type)
     {
     }
 
 private:
     const AnimatedPropertyType m_type;
 };
 
 }
 
 #endif // NewSVGProperty_h