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

Source/core/animation/RectSVGInterpolation.cpp

Index: Source/core/animation/RectSVGInterpolation.cpp
diff --git a/Source/core/animation/RectSVGInterpolation.cpp b/Source/core/animation/RectSVGInterpolation.cpp
index 94f92befa78c50da50a7647cc395eb6ab59b6641..5159c1691e3a7a226c5cefb58058068e4c7e9fdc 100644
--- a/Source/core/animation/RectSVGInterpolation.cpp
+++ b/Source/core/animation/RectSVGInterpolation.cpp
@@ -9,15 +9,15 @@
 
 namespace blink {
 
-PassOwnPtrWillBeRawPtr<InterpolableValue> RectSVGInterpolation::toInterpolableValue(SVGPropertyBase* value)
+InterpolableValue* RectSVGInterpolation::toInterpolableValue(SVGPropertyBase* value)
 {
     RefPtrWillBeRawPtr<SVGRect> rect = toSVGRect(value);
     float element[] = { rect->x(), rect->y(), rect->width(), rect->height() };
-    OwnPtrWillBeRawPtr<InterpolableList> result = InterpolableList::create(WTF_ARRAY_LENGTH(element));
+    InterpolableList* result = InterpolableList::create(WTF_ARRAY_LENGTH(element));
     for (size_t i = 0; i < WTF_ARRAY_LENGTH(element); i++) {
         result->set(i, InterpolableNumber::create(element[i]));
     }
-    return result.release();
+    return result;
 }
 
 PassRefPtrWillBeRawPtr<SVGRect> RectSVGInterpolation::fromInterpolableValue(const InterpolableValue& value)