Web Animations API: Deferred computation of interpolated values

Source/core/core.gypi

Index: Source/core/core.gypi
diff --git a/Source/core/core.gypi b/Source/core/core.gypi
index 4f92d84f2a1dde9bdda8286b8d8904fbdaca451f..f9554c516283d72fc64cca6a832e25364b2307a2 100644
--- a/Source/core/core.gypi
+++ b/Source/core/core.gypi
@@ -642,12 +642,16 @@
             'animation/InertAnimation.h',
             'animation/InterpolableValue.cpp',
             'animation/InterpolableValue.h',
+            'animation/InterpolableValuePromise.cpp',
+            'animation/InterpolableValuePromise.h',
             'animation/Interpolation.cpp',
             'animation/Interpolation.h',
             'animation/InterpolationEffect.cpp',
             'animation/InterpolationEffect.h',
             'animation/KeyframeEffectModel.cpp',
             'animation/KeyframeEffectModel.h',
+            'animation/LegacyStyleInterpolation.cpp',
+            'animation/LegacyStyleInterpolation.h',
             'animation/SampledEffect.cpp',
             'animation/SampledEffect.h',
             'animation/StringKeyframe.cpp',
@@ -3330,6 +3334,7 @@
             'animation/EffectInputTest.cpp',
             'animation/InterpolationEffectTest.cpp',
             'animation/InterpolationTest.cpp',
+            'animation/InterpolableValuePromiseTest.cpp',
             'animation/InterpolableValueTest.cpp',
             'animation/KeyframeEffectModelTest.cpp',
             'animation/TimedItemCalculationsTest.cpp',