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

Source/core/animation/animatable/AnimatableLengthSize.h

Index: Source/core/animation/animatable/AnimatableLengthSize.h
diff --git a/Source/core/animation/animatable/AnimatableLengthSize.h b/Source/core/animation/animatable/AnimatableLengthSize.h
index 343be6dcd208f189d5b83b755b61725166c8a20e..9e3297debf75882c50e530cfd55659c2c794f747 100644
--- a/Source/core/animation/animatable/AnimatableLengthSize.h
+++ b/Source/core/animation/animatable/AnimatableLengthSize.h
@@ -38,9 +38,9 @@ namespace blink {
 class AnimatableLengthSize final : public AnimatableValue {
 public:
     virtual ~AnimatableLengthSize() { }
-    static PassRefPtrWillBeRawPtr<AnimatableLengthSize> create(PassRefPtrWillBeRawPtr<AnimatableValue> width, PassRefPtrWillBeRawPtr<AnimatableValue> height)
+    static AnimatableLengthSize* create(AnimatableValue* width, AnimatableValue* height)
     {
-        return adoptRefWillBeNoop(new AnimatableLengthSize(width, height));
+        return new AnimatableLengthSize(width, height);
     }
     const AnimatableValue* width() const { return m_width.get(); }
     const AnimatableValue* height() const { return m_height.get(); }
@@ -48,10 +48,10 @@ public:
     DECLARE_VIRTUAL_TRACE();
 
 protected:
-    virtual PassRefPtrWillBeRawPtr<AnimatableValue> interpolateTo(const AnimatableValue*, double fraction) const override;
+    virtual AnimatableValue* interpolateTo(const AnimatableValue*, double fraction) const override;
 
 private:
-    AnimatableLengthSize(PassRefPtrWillBeRawPtr<AnimatableValue> width, PassRefPtrWillBeRawPtr<AnimatableValue> height)
+    AnimatableLengthSize(AnimatableValue* width, AnimatableValue* height)
         : m_width(width)
         , m_height(height)
     {
@@ -59,8 +59,8 @@ private:
     virtual AnimatableType type() const override { return TypeLengthSize; }
     virtual bool equalTo(const AnimatableValue*) const override;
 
-    RefPtrWillBeMember<AnimatableValue> m_width;
-    RefPtrWillBeMember<AnimatableValue> m_height;
+    Member<AnimatableValue> m_width;
+    Member<AnimatableValue> m_height;
 };
 
 DEFINE_ANIMATABLE_VALUE_TYPE_CASTS(AnimatableLengthSize, isLengthSize());