Remove unused AnimatableValue types

third_party/WebKit/Source/core/animation/animatable/AnimatableDouble.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 24 matching lines @@
 
 namespace blink {
 
 PassRefPtr<AnimatableValue> AnimatableDouble::InterpolateTo(
     const AnimatableValue* value,
     double fraction) const {
   const AnimatableDouble* other = ToAnimatableDouble(value);
   return AnimatableDouble::Create(Blend(number_, other->number_, fraction));
 }
 
-bool AnimatableDouble::EqualTo(const AnimatableValue* value) const {
-  return number_ == ToAnimatableDouble(value)->number_;
-}
-
 }  // namespace blink