Add foundation for removing AnimatableValues from StyleInterpolation

Source/core/animation/InvalidatableStyleInterpolation.h

Index: Source/core/animation/InvalidatableStyleInterpolation.h
diff --git a/Source/core/animation/InvalidatableStyleInterpolation.h b/Source/core/animation/InvalidatableStyleInterpolation.h
new file mode 100644
index 0000000000000000000000000000000000000000..807a3b8d2af45374562bc22d0a4d34414d4e99b5
--- /dev/null
+++ b/Source/core/animation/InvalidatableStyleInterpolation.h
@@ -0,0 +1,64 @@
+// Copyright 2015 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 InvalidatableStyleInterpolation_h
+#define InvalidatableStyleInterpolation_h
+
+#include "core/animation/AnimationType.h"
+#include "core/animation/AnimationValue.h"
+#include "core/animation/PrimitiveInterpolation.h"
+#include "core/animation/StyleInterpolation.h"
+
+namespace blink {
+
+// TODO(alancutter): This class will replace *StyleInterpolation, SVGInterpolation, Interpolation.
+// For now it needs to distinguish itself during the refactor and temporarily has an ugly name.
+// TODO(alancutter): Make this class generic for any animation environment so it can be reused for SVG animations.
+class CORE_EXPORT InvalidatableStyleInterpolation : public StyleInterpolation {
+public:
+    static PassRefPtrWillBeRawPtr<InvalidatableStyleInterpolation> create(
+        const Vector<const AnimationType*>& animationTypes,
+        const CSSPropertySpecificKeyframe& startKeyframe,
+        const CSSPropertySpecificKeyframe& endKeyframe)
+    {
+        return adoptRefWillBeNoop(new InvalidatableStyleInterpolation(animationTypes, startKeyframe, endKeyframe));
+    }
+
+    virtual void interpolate(int iteration, double fraction);
+    virtual void apply(StyleResolverState&) const;
+
+    virtual bool isInvalidatableStyleInterpolation() const { return true; }
+
+    DEFINE_INLINE_VIRTUAL_TRACE()
+    {
+        StyleInterpolation::trace(visitor);
+        visitor->trace(m_cachedConversion);
+        visitor->trace(m_cachedValue);
+    }
+
+private:
+    InvalidatableStyleInterpolation(
+        const Vector<const AnimationType*>& animationTypes,
+        const CSSPropertySpecificKeyframe& startKeyframe,
+        const CSSPropertySpecificKeyframe& endKeyframe);
+
+    void ensureValidInterpolation(const StyleResolverState&) const;
+    bool isCacheValid(const StyleResolverState&) const;
+    bool maybeCachePairwiseConversion(const StyleResolverState*) const;
+    PassOwnPtrWillBeRawPtr<FlipPrimitiveInterpolation::Side> convertSingleKeyframe(const CSSPropertySpecificKeyframe&, const StyleResolverState&) const;
+
+    const Vector<const AnimationType*>& m_animationTypes;
+    const CSSPropertySpecificKeyframe& m_startKeyframe;
+    const CSSPropertySpecificKeyframe& m_endKeyframe;
+    double m_currentFraction;
+    mutable OwnPtrWillBeMember<PrimitiveInterpolation> m_cachedConversion;
+    mutable AnimationType::ConversionCheckers m_conversionCheckers;
+    mutable AnimationValue m_cachedValue;
+};
+
+DEFINE_TYPE_CASTS(InvalidatableStyleInterpolation, Interpolation, value, value->isInvalidatableStyleInterpolation(), value.isInvalidatableStyleInterpolation());
+
+} // namespace blink
+
+#endif // InvalidatableStyleInterpolation_h