Remove some unused functions in core

Source/core/animation/animatable/AnimatableDoubleTest.cpp

Index: Source/core/animation/animatable/AnimatableDoubleTest.cpp
diff --git a/Source/core/animation/animatable/AnimatableDoubleTest.cpp b/Source/core/animation/animatable/AnimatableDoubleTest.cpp
index 9440d25dd0d6d1054201cdc956a60d652c073b1d..0808838831b1436dfde885020a232fbd32bf71c5 100644
--- a/Source/core/animation/animatable/AnimatableDoubleTest.cpp
+++ b/Source/core/animation/animatable/AnimatableDoubleTest.cpp
@@ -69,15 +69,4 @@ TEST(AnimationAnimatableDoubleTest, Interpolate)
     EXPECT_EQ(25, toAnimatableDouble(AnimatableValue::interpolate(from10.get(), to20.get(), 1.5).get())->toDouble());
 }
 
-TEST(AnimationAnimatableDoubleTest, Distance)
-{
-    RefPtrWillBeRawPtr<AnimatableDouble> first = AnimatableDouble::create(-1.5);
-    RefPtrWillBeRawPtr<AnimatableDouble> second = AnimatableDouble::create(2.25);
-    RefPtrWillBeRawPtr<AnimatableDouble> third = AnimatableDouble::create(3);
-
-    EXPECT_DOUBLE_EQ(3.75, AnimatableValue::distance(first.get(), second.get()));
-    EXPECT_DOUBLE_EQ(0.75, AnimatableValue::distance(second.get(), third.get()));
-    EXPECT_DOUBLE_EQ(4.5, AnimatableValue::distance(third.get(), first.get()));
-}
-
 }