Web Animations: Remove confusing interpolation subdirectory.

Source/core/animation/AnimationStackTest.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/AnimationStack.h"
 
 #include "core/animation/ActiveAnimations.h"
 #include "core/animation/AnimationClock.h"
 #include "core/animation/AnimationTimeline.h"
 #include "core/animation/KeyframeEffectModel.h"
+#include "core/animation/LegacyStyleInterpolation.h"
 #include "core/animation/animatable/AnimatableDouble.h"
-#include "core/animation/interpolation/LegacyStyleInterpolation.h"
 #include <gtest/gtest.h>
 
 namespace blink {
 
 class AnimationAnimationStackTest : public ::testing::Test {
 protected:
     virtual void SetUp()
     {
         document = Document::create();
         document->animationClock().resetTimeForTesting();
@@ skipping 130 matching lines @@
 
     updateTimeline(17);
     Heap::collectAllGarbage();
     interpolations = AnimationStack::activeInterpolations(&element->activeAnimations()->defaultStack(), 0, 0, Animation::DefaultPriority, 0);
     EXPECT_TRUE(interpolationValue(interpolations.get(CSSPropertyFontSize))->equals(AnimatableDouble::create(2).get()));
     EXPECT_EQ(1u, effects().size());
     EXPECT_EQ(6, effects()[0]->sortInfo().startTime());
 }
 
 }