[Oilpan] Migrate most classes under core/animations to Oilpan heap.

Source/core/animation/VisibilityStyleInterpolation.h

 #ifndef VisibilityStyleInterpolation_h
 #define VisibilityStyleInterpolation_h
 
 #include "core/CSSValueKeywords.h"
 #include "core/CoreExport.h"
 #include "core/animation/StyleInterpolation.h"
 #include "core/css/CSSPrimitiveValue.h"
 
 namespace blink {
 
 class CORE_EXPORT VisibilityStyleInterpolation : public StyleInterpolation {
 public:
-    static PassRefPtrWillBeRawPtr<VisibilityStyleInterpolation> create(const CSSValue& start, const CSSValue& end, CSSPropertyID id)
+    static VisibilityStyleInterpolation* create(const CSSValue& start, const CSSValue& end, CSSPropertyID id)
     {
-        RefPtrWillBeRawPtr<VisibilityStyleInterpolation> interpolation = adoptRefWillBeNoop(new VisibilityStyleInterpolation(
-            visibilityToInterpolableValue(start), visibilityToInterpolableValue(end), id));
+        VisibilityStyleInterpolation* interpolation = new VisibilityStyleInterpolation(visibilityToInterpolableValue(start), visibilityToInterpolableValue(end), id);
         if (!isVisible(start)) {
             interpolation->m_notVisible = toCSSPrimitiveValue(start).getValueID();
         } else if (!isVisible(end)) {
             interpolation->m_notVisible = toCSSPrimitiveValue(end).getValueID();
         }
 
-        return interpolation.release();
+        return interpolation;
     }
 
     static bool canCreateFrom(const CSSValue&);
     static bool isVisible(const CSSValue&);
 
     void apply(StyleResolverState&) const override;
     DECLARE_VIRTUAL_TRACE();
 
 private:
-    VisibilityStyleInterpolation(PassOwnPtrWillBeRawPtr<InterpolableValue> start, PassOwnPtrWillBeRawPtr<InterpolableValue> end, CSSPropertyID id)
+    VisibilityStyleInterpolation(InterpolableValue* start, InterpolableValue* end, CSSPropertyID id)
         : StyleInterpolation(start, end, id)
         , m_notVisible(CSSValueVisible)
     {
     }
 
-    static PassOwnPtrWillBeRawPtr<InterpolableValue> visibilityToInterpolableValue(const CSSValue&);
+    static InterpolableValue* visibilityToInterpolableValue(const CSSValue&);
     static PassRefPtrWillBeRawPtr<CSSValue> interpolableValueToVisibility(InterpolableValue*, CSSValueID);
 
     CSSValueID m_notVisible;
 
     friend class AnimationVisibilityStyleInterpolationTest;
 };
 }
 
 #endif