WIP: Implement CSS transitions on top of InterpolationTypes instead of AnimatableValues

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

Index: third_party/WebKit/Source/core/animation/PrimitiveInterpolation.h
diff --git a/third_party/WebKit/Source/core/animation/PrimitiveInterpolation.h b/third_party/WebKit/Source/core/animation/PrimitiveInterpolation.h
index 5a74b4be30e4e3ff4ad41752785bbcb3317b5935..76951c1ddb5cdeede1e23c2edc79679a441471f5 100644
--- a/third_party/WebKit/Source/core/animation/PrimitiveInterpolation.h
+++ b/third_party/WebKit/Source/core/animation/PrimitiveInterpolation.h
@@ -5,6 +5,7 @@
 #ifndef PrimitiveInterpolation_h
 #define PrimitiveInterpolation_h
 
+#include "core/animation/PairwiseInterpolationValue.h"
 #include "core/animation/TypedInterpolationValue.h"
 #include "platform/animation/AnimationUtilities.h"
 #include "platform/heap/Handle.h"
@@ -38,43 +39,39 @@ class PairwisePrimitiveInterpolation : public PrimitiveInterpolation {
 public:
     ~PairwisePrimitiveInterpolation() override { }
 
-    static std::unique_ptr<PairwisePrimitiveInterpolation> create(const InterpolationType& type, std::unique_ptr<InterpolableValue> start, std::unique_ptr<InterpolableValue> end, PassRefPtr<NonInterpolableValue> nonInterpolableValue)
+    static std::unique_ptr<PairwisePrimitiveInterpolation> create(const InterpolationType& type, PairwiseInterpolationValue&& pairwiseInterpolationValue)
     {
-        return wrapUnique(new PairwisePrimitiveInterpolation(type, std::move(start), std::move(end), nonInterpolableValue));
+        return wrapUnique(new PairwisePrimitiveInterpolation(type, std::move(pairwiseInterpolationValue)));
     }
 
     const InterpolationType& type() const { return m_type; }
 
     std::unique_ptr<TypedInterpolationValue> initialValue() const
     {
-        return TypedInterpolationValue::create(m_type, m_start->clone(), m_nonInterpolableValue);
+        return TypedInterpolationValue::create(m_type, InterpolationValue(m_pairwise.startInterpolableValue->clone(), m_pairwise.nonInterpolableValue));
     }
 
-private:
-    PairwisePrimitiveInterpolation(const InterpolationType& type, std::unique_ptr<InterpolableValue> start, std::unique_ptr<InterpolableValue> end, PassRefPtr<NonInterpolableValue> nonInterpolableValue)
-        : m_type(type)
-        , m_start(std::move(start))
-        , m_end(std::move(end))
-        , m_nonInterpolableValue(nonInterpolableValue)
+    void interpolateValue(double fraction, std::unique_ptr<TypedInterpolationValue>& result) const final
     {
-        ASSERT(m_start);
-        ASSERT(m_end);
+        DCHECK(result);
+        DCHECK(&result->type() == &m_type);
+        DCHECK(result->getNonInterpolableValue() == m_pairwise.nonInterpolableValue.get());
+        m_pairwise.startInterpolableValue->interpolate(
+            *m_pairwise.endInterpolableValue, fraction, *result->mutableValue().interpolableValue);
     }
 
-    void interpolateValue(double fraction, std::unique_ptr<TypedInterpolationValue>& result) const final
+private:
+    PairwisePrimitiveInterpolation(const InterpolationType& type, PairwiseInterpolationValue&& pairwiseInterpolationValue)
+        : m_type(type)
+        , m_pairwise(std::move(pairwiseInterpolationValue))
     {
-        ASSERT(result);
-        ASSERT(&result->type() == &m_type);
-        ASSERT(result->getNonInterpolableValue() == m_nonInterpolableValue.get());
-        m_start->interpolate(*m_end, fraction, *result->mutableValue().interpolableValue);
+        DCHECK(m_pairwise);
     }
 
     double interpolateUnderlyingFraction(double start, double end, double fraction) const final { return blend(start, end, fraction); }
 
     const InterpolationType& m_type;
-    std::unique_ptr<InterpolableValue> m_start;
-    std::unique_ptr<InterpolableValue> m_end;
-    RefPtr<NonInterpolableValue> m_nonInterpolableValue;
+    PairwiseInterpolationValue m_pairwise;
 };
 
 // Represents a pair of incompatible keyframes that fall back to 50% flip behaviour eg. "auto" and "0px".