Remove some unused functions in core

Source/core/animation/animatable/AnimatableColorTest.cpp

Index: Source/core/animation/animatable/AnimatableColorTest.cpp
diff --git a/Source/core/animation/animatable/AnimatableColorTest.cpp b/Source/core/animation/animatable/AnimatableColorTest.cpp
index 416675ea50c14037e5161f14031a88b2d3c410f5..506536db82c6296fc769f8186587a967aa750aeb 100644
--- a/Source/core/animation/animatable/AnimatableColorTest.cpp
+++ b/Source/core/animation/animatable/AnimatableColorTest.cpp
@@ -65,16 +65,4 @@ TEST(AnimationAnimatableColorTest, Interpolate)
     EXPECT_EQ(AnimatableColorImpl(Color(0x10204080)).interpolateTo(Color(0x104080C0), 0.5).toColor().rgb(), 0x103060A0u);
 }
 
-TEST(AnimationAnimatableColorTest, Distance)
-{
-    EXPECT_NEAR(1.0, AnimatableColorImpl(Color(0xFF000000)).distanceTo(Color(0xFFFF0000)), 0.00000001);
-    EXPECT_NEAR(13.0 / 255, AnimatableColorImpl(Color(0xFF53647C)).distanceTo(Color(0xFF506070)), 0.00000001);
-    EXPECT_NEAR(60.0 / 255, AnimatableColorImpl(Color(0x3C000000)).distanceTo(Color(0x00FFFFFF)), 0.00000001);
-    EXPECT_NEAR(60.0 / 255, AnimatableColorImpl(Color(0x3C000000)).distanceTo(Color(0x3C00FF00)), 0.00000001);
-
-    RefPtrWillBeRawPtr<AnimatableColor> first = AnimatableColor::create(AnimatableColorImpl(Color(0xFF53647C)), AnimatableColorImpl(Color(0xFF000000)));
-    RefPtrWillBeRawPtr<AnimatableColor> second = AnimatableColor::create(AnimatableColorImpl(Color(0xFF506070)), AnimatableColorImpl(Color(0xFF000000)));
-    EXPECT_NEAR(13.0 / 255, AnimatableValue::distance(first.get(), second.get()), 0.00000001);
-}
-
 }