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

Source/core/animation/IntegerOptionalIntegerSVGInterpolation.cpp

 // Copyright 2015 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/IntegerOptionalIntegerSVGInterpolation.h"
 
 #include "core/SVGNames.h"
 
 namespace blink {
 
 namespace {
 
 // For order, the values must be integers greater than zero.
 // For filterRes, negative values are an error. Zero values disable rendering of the element which referenced the filter.
 PassRefPtrWillBeRawPtr<SVGInteger> toPositiveInteger(const InterpolableValue* number, int min)
 {
     return SVGInteger::create(clampTo<int>(roundf(toInterpolableNumber(number)->value()), min));
 }
 
 } // namespace
 
-PassOwnPtrWillBeRawPtr<InterpolableValue> IntegerOptionalIntegerSVGInterpolation::toInterpolableValue(SVGPropertyBase* value)
+InterpolableValue* IntegerOptionalIntegerSVGInterpolation::toInterpolableValue(SVGPropertyBase* value)
 {
     RefPtrWillBeRawPtr<SVGIntegerOptionalInteger> integerOptionalInteger = toSVGIntegerOptionalInteger(value);
-    OwnPtrWillBeRawPtr<InterpolableList> result = InterpolableList::create(2);
+    InterpolableList* result = InterpolableList::create(2);
     result->set(0, InterpolableNumber::create(integerOptionalInteger->firstInteger()->value()));
     result->set(1, InterpolableNumber::create(integerOptionalInteger->secondInteger()->value()));
-    return result.release();
+    return result;
 }
 
 PassRefPtrWillBeRawPtr<SVGIntegerOptionalInteger> IntegerOptionalIntegerSVGInterpolation::fromInterpolableValue(const InterpolableValue& value, int min)
 {
     const InterpolableList& list = toInterpolableList(value);
     return SVGIntegerOptionalInteger::create(
         toPositiveInteger(list.get(0), min),
         toPositiveInteger(list.get(1), min));
 }
 
 }