Add foundation for removing AnimatableValues from StyleInterpolation

Source/core/animation/AnimationType.h

Index: Source/core/animation/AnimationType.h
diff --git a/Source/core/animation/AnimationType.h b/Source/core/animation/AnimationType.h
new file mode 100644
index 0000000000000000000000000000000000000000..3f424ee9f30bceacc9aa4de968778cf2a4b1aa88
--- /dev/null
+++ b/Source/core/animation/AnimationType.h
@@ -0,0 +1,37 @@
+// 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 AnimationType_h
+#define AnimationType_h
+
+#include "core/animation/AnimationConversion.h"
+#include "core/animation/InterpolableValue.h"
+#include "core/animation/NonInterpolableValue.h"
+#include "core/animation/StringKeyframe.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class StyleResolverState;
+
+class AnimationType {
+public:
+    virtual CSSPropertyID property() const = 0;
+
+    virtual PassOwnPtrWillBeRawPtr<PairwiseAnimationConversion> maybeConvertPairwise(const CSSPropertySpecificKeyframe& startKeyframe, const CSSPropertySpecificKeyframe& endKeyframe, const StyleResolverState*) const
+    {
+        return nullptr;
+    }
+
+    virtual PassOwnPtrWillBeRawPtr<AnimationConversionHalf> maybeConvertSingle(const CSSPropertySpecificKeyframe&, const StyleResolverState*) const
+    {
+        return nullptr;
+    }
+
+    virtual void apply(const InterpolableValue&, const NonInterpolableValue*, StyleResolverState&) const = 0;
+};
+
+} // namespace blink
+
+#endif // AnimationType_h