Web Animations: Refactor KeyframeEffectModel to work via an InterpolationEffect.

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/animation/InterpolableValue.h"
-#include "core/css/resolver/StyleResolverState.h"
 #include "wtf/RefCounted.h"
 
 namespace WebCore {
 
+class StyleResolverState;
+
 class Interpolation : public RefCounted<Interpolation> {
 public:
     static PassRefPtr<Interpolation> create(PassOwnPtr<InterpolableValue> start, PassOwnPtr<InterpolableValue> end)
     {
         return adoptRef(new Interpolation(start, end));
     }
 
     void interpolate(int iteration, double fraction) const;
 
+    virtual bool isStyleInterpolation() const { return false; }
+    virtual bool isLegacyStyleInterpolation() const { return false; }
+
+    virtual ~Interpolation()
+    { }
+
 protected:
     const OwnPtr<InterpolableValue> m_start;
     const OwnPtr<InterpolableValue> m_end;
 
     mutable double m_cachedFraction;
     mutable int m_cachedIteration;
     mutable OwnPtr<InterpolableValue> m_cachedValue;
 
     Interpolation(PassOwnPtr<InterpolableValue> start, PassOwnPtr<InterpolableValue> end);
 
 private:
     InterpolableValue* getCachedValueForTesting() const { return m_cachedValue.get(); }
 
     friend class AnimationInterpolableValueTest;
     friend class AnimationInterpolationEffectTest;
+
 };
 
 class StyleInterpolation : public Interpolation {
 public:
     // 1) convert m_cachedValue into an X
     // 2) shove X into StyleResolverState
     // X can be:
     // (1) a CSSValue (and applied via StyleBuilder::applyProperty)
     // (2) an AnimatableValue (and applied via // AnimatedStyleBuilder::applyProperty)
     // (3) a custom value that is inserted directly into the StyleResolverState.
-    virtual void apply(StyleResolverState&) = 0;
+    virtual void apply(StyleResolverState&) const = 0;
+
+    virtual bool isStyleInterpolation() const OVERRIDE FINAL { return true; }
+
+    CSSPropertyID id() const { return m_id; }
 
 protected:
     CSSPropertyID m_id;
 
     StyleInterpolation(PassOwnPtr<InterpolableValue> start, PassOwnPtr<InterpolableValue> end, CSSPropertyID id)
         : Interpolation(start, end)
         , m_id(id)
     { }
 };
 
+class LegacyStyleInterpolation : public StyleInterpolation {
+public:
+    static PassRefPtr<LegacyStyleInterpolation> create(PassRefPtr<AnimatableValue> start, PassRefPtr<AnimatableValue> end, CSSPropertyID id)
+    {
+        return adoptRef(new LegacyStyleInterpolation(InterpolableAnimatableValue::create(start), InterpolableAnimatableValue::create(end), id));
+    }
+
+    virtual void apply(StyleResolverState&) const;
+
+    virtual bool isLegacyStyleInterpolation() const OVERRIDE FINAL { return true; }
+    AnimatableValue* currentValue() const
+    {
+        InterpolableAnimatableValue *value = static_cast<InterpolableAnimatableValue *>(m_cachedValue.get());
+        return value->value();
+    }
+
+private:
+    LegacyStyleInterpolation(PassOwnPtr<InterpolableValue> start, PassOwnPtr<InterpolableValue> end, CSSPropertyID id)
+        : StyleInterpolation(start, end, id)
+    { }
+};
+
+DEFINE_TYPE_CASTS(StyleInterpolation, Interpolation, value, value->isStyleInterpolation(), value.isStyleInterpolation());
+DEFINE_TYPE_CASTS(LegacyStyleInterpolation, Interpolation, value, value->isLegacyStyleInterpolation(), value.isLegacyStyleInterpolation());
+
 }
 #endif