Remove most content from Interpolation

third_party/WebKit/Source/core/animation/Interpolation.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef Interpolation_h
 #define Interpolation_h
 
 #include "core/CoreExport.h"
 #include "core/animation/InterpolableValue.h"
 #include "wtf/Forward.h"
 #include "wtf/RefCounted.h"
 #include <memory>
 
 namespace blink {
 
 class PropertyHandle;
 
 // Represents an animation's effect between an adjacent pair of
 // PropertySpecificKeyframes.
 class CORE_EXPORT Interpolation : public RefCounted<Interpolation> {
   WTF_MAKE_NONCOPYABLE(Interpolation);
 
  public:
-  virtual ~Interpolation();
+  virtual ~Interpolation() {}
 
-  virtual void interpolate(int iteration, double fraction);
+  virtual void interpolate(int iteration, double fraction) = 0;
 
   virtual bool isInvalidatableInterpolation() const { return false; }
   virtual bool isLegacyStyleInterpolation() const { return false; }
 
   virtual PropertyHandle getProperty() const = 0;
   virtual bool dependsOnUnderlyingValue() const { return false; }
 
  protected:
-  const std::unique_ptr<InterpolableValue> m_start;
-  const std::unique_ptr<InterpolableValue> m_end;
+  Interpolation() {}
 
-  mutable double m_cachedFraction;
-  mutable int m_cachedIteration;
-  mutable std::unique_ptr<InterpolableValue> m_cachedValue;
-
-  Interpolation(std::unique_ptr<InterpolableValue> start,
-                std::unique_ptr<InterpolableValue> end);
-
- private:
-  InterpolableValue* getCachedValueForTesting() const {
-    return m_cachedValue.get();
-  }
+  virtual InterpolableValue* getCachedValueForTesting() const = 0;
 
   friend class AnimationInterpolableValueTest;
   friend class AnimationInterpolationEffectTest;
   friend class AnimationDoubleStyleInterpolationTest;
   friend class AnimationVisibilityStyleInterpolationTest;
 };
 
 using ActiveInterpolations = Vector<RefPtr<Interpolation>, 1>;
 
 }  // namespace blink
 
 #endif  // Interpolation_h