Delete unused AnimatableValue code

third_party/WebKit/Source/core/animation/animatable/AnimatableVisibility.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 19 matching lines @@
 
 #ifndef AnimatableVisibility_h
 #define AnimatableVisibility_h
 
 #include "core/CoreExport.h"
 #include "core/animation/animatable/AnimatableValue.h"
 #include "core/style/ComputedStyleConstants.h"
 
 namespace blink {
 
-class CORE_EXPORT AnimatableVisibility final : public AnimatableValue {
+class AnimatableVisibility final : public AnimatableValue {
  public:
   ~AnimatableVisibility() override {}
   static PassRefPtr<AnimatableVisibility> create(EVisibility visibility) {
     return adoptRef(new AnimatableVisibility(visibility));
   }
 
-  EVisibility visibility() const { return m_visibility; }
-
- protected:
-  PassRefPtr<AnimatableValue> interpolateTo(const AnimatableValue*,
-                                            double fraction) const override;
-  bool usesDefaultInterpolationWith(const AnimatableValue*) const override;
-
  private:
   explicit AnimatableVisibility(EVisibility visibility)
       : m_visibility(visibility) {}
   AnimatableType type() const override { return TypeVisibility; }
   bool equalTo(const AnimatableValue*) const override;
   const EVisibility m_visibility;
 };
 
 DEFINE_ANIMATABLE_VALUE_TYPE_CASTS(AnimatableVisibility, isVisibility());
 
 }  // namespace blink
 
 #endif  // AnimatableVisibility_h