Delete unused AnimatableValue code

third_party/WebKit/Source/core/animation/BUILD.gn

Index: third_party/WebKit/Source/core/animation/BUILD.gn
diff --git a/third_party/WebKit/Source/core/animation/BUILD.gn b/third_party/WebKit/Source/core/animation/BUILD.gn
index bccd78f8857a3d7a9f444d05ab079217b9fa0fb8..adb1cc29ca63d8e48291d2aacb1720af41a94d23 100644
--- a/third_party/WebKit/Source/core/animation/BUILD.gn
+++ b/third_party/WebKit/Source/core/animation/BUILD.gn
@@ -238,7 +238,6 @@ blink_core_sources("animation") {
     "animatable/AnimatableLengthPoint3D.h",
     "animatable/AnimatableLengthSize.cpp",
     "animatable/AnimatableLengthSize.h",
-    "animatable/AnimatableNeutral.h",
     "animatable/AnimatablePath.cpp",
     "animatable/AnimatablePath.h",
     "animatable/AnimatableRepeatable.cpp",
@@ -249,7 +248,6 @@ blink_core_sources("animation") {
     "animatable/AnimatableShadow.h",
     "animatable/AnimatableShapeValue.cpp",
     "animatable/AnimatableShapeValue.h",
-    "animatable/AnimatableStrokeDasharrayList.cpp",
     "animatable/AnimatableStrokeDasharrayList.h",
     "animatable/AnimatableTransform.cpp",
     "animatable/AnimatableTransform.h",