[Oilpan] Move ScrollAnimators onto oilpan heap

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

Index: third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm
diff --git a/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm b/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm
index 02e5cd16ca8d0bc0450683472f6791cd634a0701..6b77e3d40f5e0bbf5bf7141cfaa18f7f1da9f1f9 100644
--- a/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm
+++ b/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm
@@ -40,7 +40,6 @@
 #include "platform/scroll/ScrollbarThemeMacCommon.h"
 #include "platform/scroll/ScrollbarThemeMacOverlayAPI.h"
 #include "wtf/MainThread.h"
-#include "wtf/PassOwnPtr.h"
 
 using namespace blink;
 
@@ -679,9 +678,9 @@ private:
 
 namespace blink {
 
-PassOwnPtr<ScrollAnimatorBase> ScrollAnimatorBase::create(ScrollableArea* scrollableArea)
+ScrollAnimatorBase* ScrollAnimatorBase::create(ScrollableArea* scrollableArea)
 {
-    return adoptPtr(new ScrollAnimatorMac(scrollableArea));
+    return new ScrollAnimatorMac(scrollableArea);
 }
 
 ScrollAnimatorMac::ScrollAnimatorMac(ScrollableArea* scrollableArea)
@@ -704,6 +703,11 @@ ScrollAnimatorMac::ScrollAnimatorMac(ScrollableArea* scrollableArea)
 
 ScrollAnimatorMac::~ScrollAnimatorMac()
 {
+    cleanup();
+}
+
+void ScrollAnimatorMac::cleanup()
+{
     if (ScrollbarThemeMacCommon::isOverlayAPIAvailable()) {
         BEGIN_BLOCK_OBJC_EXCEPTIONS;
         [m_scrollbarPainterControllerDelegate.get() invalidate];
@@ -713,6 +717,8 @@ ScrollAnimatorMac::~ScrollAnimatorMac()
         [m_scrollAnimationHelperDelegate.get() invalidate];
         END_BLOCK_OBJC_EXCEPTIONS;
     }
+    m_initialScrollbarPaintTimer.stop();
+    m_sendContentAreaScrolledTimer.stop();
 }
 
 ScrollResultOneDimensional ScrollAnimatorMac::userScroll(ScrollbarOrientation orientation, ScrollGranularity granularity, float step, float delta)