SVG: Remove SVGAnimatedPropertyBase::startAnimation and its overrides which are already all NOOP

Source/core/svg/properties/SVGAnimatedProperty.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.
 G*     * Redistributions in binary form must reproduce the above
@@ skipping 34 matching lines @@
 
 class SVGElement;
 
 class SVGAnimatedPropertyBase : public RefCounted<SVGAnimatedPropertyBase> {
 public:
     virtual ~SVGAnimatedPropertyBase();
 
     virtual SVGPropertyBase* currentValueBase() = 0;
     virtual bool isAnimating() const = 0;
 
-    virtual void animationStarted();
     virtual PassRefPtr<SVGPropertyBase> createAnimatedValue() = 0;
     virtual void setAnimatedValue(PassRefPtr<SVGPropertyBase>) = 0;
     virtual void animationEnded();
 
     virtual bool needsSynchronizeAttribute() = 0;
     virtual void synchronizeAttribute();
 
     AnimatedPropertyType type() const
     {
         return m_type;
@@ skipping 235 matching lines @@
     // When animated:
     //     m_animValTearOff targets m_currentValue.
     //     m_baseValTearOff targets m_baseValue.
     RefPtr<TearOffType> m_baseValTearOff;
     RefPtr<TearOffType> m_animValTearOff;
 };
 
 }
 
 #endif // SVGAnimatedProperty_h