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

Source/core/animation/IntegerSVGInterpolation.h

Index: Source/core/animation/IntegerSVGInterpolation.h
diff --git a/Source/core/animation/IntegerSVGInterpolation.h b/Source/core/animation/IntegerSVGInterpolation.h
index 53187e8e383f5aff7f29d62aac3e115a2d810218..b11c889c561f9a319443c83a4d44da0a153fe623 100644
--- a/Source/core/animation/IntegerSVGInterpolation.h
+++ b/Source/core/animation/IntegerSVGInterpolation.h
@@ -12,9 +12,9 @@ namespace blink {
 
 class IntegerSVGInterpolation : public SVGInterpolation {
 public:
-    static PassRefPtrWillBeRawPtr<IntegerSVGInterpolation> create(SVGPropertyBase* start, SVGPropertyBase* end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute)
+    static IntegerSVGInterpolation* create(SVGPropertyBase* start, SVGPropertyBase* end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute)
     {
-        return adoptRefWillBeNoop(new IntegerSVGInterpolation(toInterpolableValue(start), toInterpolableValue(end), attribute));
+        return new IntegerSVGInterpolation(toInterpolableValue(start), toInterpolableValue(end), attribute);
     }
 
     PassRefPtrWillBeRawPtr<SVGPropertyBase> interpolatedValue(SVGElement&) const final
@@ -28,12 +28,12 @@ public:
     }
 
 private:
-    IntegerSVGInterpolation(PassOwnPtrWillBeRawPtr<InterpolableValue> start, PassOwnPtrWillBeRawPtr<InterpolableValue> end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute)
+    IntegerSVGInterpolation(InterpolableValue* start, InterpolableValue* end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute)
         : SVGInterpolation(start, end, attribute)
     {
     }
 
-    static PassOwnPtrWillBeRawPtr<InterpolableValue> toInterpolableValue(SVGPropertyBase* value)
+    static InterpolableValue* toInterpolableValue(SVGPropertyBase* value)
     {
         return InterpolableNumber::create(toSVGInteger(value)->value());
     }