Web Animations: Remove confusing interpolation subdirectory.

Source/core/animation/StringKeyframe.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/StringKeyframe.h"
 
+#include "core/animation/DefaultStyleInterpolation.h"
+#include "core/animation/DeferredLegacyStyleInterpolation.h"
+#include "core/animation/LegacyStyleInterpolation.h"
+#include "core/animation/LengthStyleInterpolation.h"
 #include "core/animation/css/CSSAnimations.h"
-#include "core/animation/interpolation/DefaultStyleInterpolation.h"
-#include "core/animation/interpolation/DeferredLegacyStyleInterpolation.h"
-#include "core/animation/interpolation/LegacyStyleInterpolation.h"
-#include "core/animation/interpolation/LengthStyleInterpolation.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/rendering/style/RenderStyle.h"
 
 namespace blink {
 
 StringKeyframe::StringKeyframe(const StringKeyframe& copyFrom)
     : Keyframe(copyFrom.m_offset, copyFrom.m_composite, copyFrom.m_easing)
     , m_propertySet(copyFrom.m_propertySet->mutableCopy())
 {
 }
@@ skipping 120 matching lines @@
 }
 
 void StringKeyframe::PropertySpecificKeyframe::trace(Visitor* visitor)
 {
     visitor->trace(m_value);
     visitor->trace(m_animatableValueCache);
     Keyframe::PropertySpecificKeyframe::trace(visitor);
 }
 
 }