Web Animations: Remove confusing interpolation subdirectory.

Source/core/animation/LengthStyleInterpolationTest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
-#include "core/animation/interpolation/LengthStyleInterpolation.h"
+#include "core/animation/LengthStyleInterpolation.h"
 
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/css/StylePropertySet.h"
 
 #include <gtest/gtest.h>
 
 namespace blink {
 
 class AnimationLengthStyleInterpolationTest : public ::testing::Test {
 protected:
@@ skipping 93 matching lines @@
 TEST_F(AnimationLengthStyleInterpolationTest, MultipleUnits)
 {
     CSSLengthArray actual, expectation;
     initLengthArray(expectation);
     OwnPtrWillBeRawPtr<InterpolableList> list = createInterpolableLength(0, 10, 0, 10, 0, 10, 0, 10, 0, 10);
     toCSSPrimitiveValue(interpolableValueToLength(list.get(), ValueRangeAll).get())->accumulateLengthArray(expectation);
     EXPECT_TRUE(lengthArraysEqual(expectation, setLengthArray(actual, "calc(10%% + 10ex + 10ch + 10vh + 10vmax)")));
 }
 
 }