Add foundation for removing AnimatableValues from StyleInterpolation

Source/core/core.gypi

Index: Source/core/core.gypi
diff --git a/Source/core/core.gypi b/Source/core/core.gypi
index 0c79b124ad564b6d31c8f92071bacc3715982333..3467170458d54e9454dd20b7b45551a6f602dcfd 100644
--- a/Source/core/core.gypi
+++ b/Source/core/core.gypi
@@ -855,6 +855,7 @@
             'animation/AnimationClock.cpp',
             'animation/AnimationClock.h',
             'animation/EffectModel.h',
+            'animation/AnimationConversion.h',
             'animation/AnimationInputHelpers.cpp',
             'animation/AnimationInputHelpers.h',
             'animation/AnimationEffect.cpp',
@@ -869,6 +870,8 @@
             'animation/AnimationTimeline.h',
             'animation/AnimationTranslationUtil.cpp',
             'animation/AnimationTranslationUtil.h',
+            'animation/AnimationType.h',
+            'animation/AnimationValue.h',
             'animation/CompositorAnimations.cpp',
             'animation/CompositorAnimations.h',
             'animation/CompositorAnimationsImpl.h',
@@ -877,6 +880,8 @@
             'animation/ColorStyleInterpolation.cpp',
             'animation/ColorStyleInterpolation.h',
             'animation/ConstantStyleInterpolation.h',
+            'animation/DefaultAnimationType.cpp',
+            'animation/DefaultAnimationType.h',
             'animation/DefaultSVGInterpolation.cpp',
             'animation/DefaultSVGInterpolation.h',
             'animation/DeferredLegacyStyleInterpolation.cpp',
@@ -908,6 +913,8 @@
             'animation/Interpolation.h',
             'animation/InterpolationEffect.cpp',
             'animation/InterpolationEffect.h',
+            'animation/InvalidatableStyleInterpolation.cpp',
+            'animation/InvalidatableStyleInterpolation.h',
             'animation/KeyframeEffectModel.cpp',
             'animation/KeyframeEffectModel.h',
             'animation/LegacyStyleInterpolation.h',
@@ -919,6 +926,7 @@
             'animation/LengthSVGInterpolation.h',
             'animation/LengthStyleInterpolation.cpp',
             'animation/LengthStyleInterpolation.h',
+            'animation/NonInterpolableValue.h',
             'animation/NumberOptionalNumberSVGInterpolation.h',
             'animation/NumberSVGInterpolation.cpp',
             'animation/NumberSVGInterpolation.h',