[Oilpan] Move ScrollAnimators onto oilpan heap

third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.h

Index: third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.h
diff --git a/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.h b/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.h
index e324f1b826bf2bf1ca22c861547e7b2228eac596..eccad162ca5eeb933924e3f94e889de6cd7f05af 100644
--- a/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.h
+++ b/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.h
@@ -30,6 +30,7 @@
 #include "platform/geometry/FloatPoint.h"
 #include "platform/geometry/FloatSize.h"
 #include "platform/geometry/IntRect.h"
+#include "platform/heap/Handle.h"
 #include "platform/scroll/ScrollAnimatorBase.h"
 #include "wtf/RetainPtr.h"
 
@@ -44,11 +45,13 @@ namespace blink {
 class Scrollbar;
 
 class PLATFORM_EXPORT ScrollAnimatorMac : public ScrollAnimatorBase {
-
+    USING_PRE_FINALIZER(ScrollAnimatorMac, cleanup);
 public:
     ScrollAnimatorMac(ScrollableArea*);
     ~ScrollAnimatorMac() override;
 
+    void cleanup() override;
+
     void immediateScrollToPointForScrollAnimation(const FloatPoint& newPosition);
     bool haveScrolledSincePageLoad() const { return m_haveScrolledSincePageLoad; }
 
@@ -64,6 +67,11 @@ public:
 
     static bool canUseCoordinatedScrollbar();
 
+    DEFINE_INLINE_VIRTUAL_TRACE()
+    {
+        ScrollAnimatorBase::trace(visitor);
+    }
+
 private:
     RetainPtr<id> m_scrollAnimationHelper;
     RetainPtr<WebScrollAnimationHelperDelegate> m_scrollAnimationHelperDelegate;