Delete unused AnimatableValue code

third_party/WebKit/Source/core/animation/animatable/AnimatableLength.cpp

 /*
  * 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 46 matching lines @@
 
 Length AnimatableLength::getLength(float zoom, ValueRange range) const {
   if (!m_hasPercent)
     return Length(clampNumber(m_pixels, range) * zoom, Fixed);
   if (!m_hasPixels)
     return Length(clampNumber(m_percent, range), Percent);
   return Length(CalculationValue::create(
       PixelsAndPercent(m_pixels * zoom, m_percent), range));
 }
 
-PassRefPtr<AnimatableValue> AnimatableLength::interpolateTo(
-    const AnimatableValue* value,
-    double fraction) const {
-  const AnimatableLength* length = toAnimatableLength(value);
-  return create(blend(m_pixels, length->m_pixels, fraction),
-                blend(m_percent, length->m_percent, fraction),
-                m_hasPixels || length->m_hasPixels,
-                m_hasPercent || length->m_hasPercent);
-}
-
 bool AnimatableLength::equalTo(const AnimatableValue* value) const {
   const AnimatableLength* length = toAnimatableLength(value);
   return m_pixels == length->m_pixels && m_percent == length->m_percent &&
          m_hasPixels == length->m_hasPixels &&
          m_hasPercent == length->m_hasPercent;
 }
 
 }  // namespace blink