Move the Widget hierarchy to the Oilpan heap.

Source/platform/mac/ScrollAnimatorMac.mm

 /*
  * Copyright (C) 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 23 matching lines @@
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/IntRect.h"
 #include "platform/mac/BlockExceptions.h"
 #include "platform/mac/NSScrollerImpDetails.h"
 #include "platform/scroll/ScrollView.h"
 #include "platform/scroll/ScrollableArea.h"
 #include "platform/scroll/ScrollbarTheme.h"
 #include "platform/scroll/ScrollbarThemeMacCommon.h"
 #include "platform/scroll/ScrollbarThemeMacOverlayAPI.h"
 #include "wtf/MainThread.h"
-#include "wtf/PassOwnPtr.h"
+#include "wtf/PassRefPtr.h"
 
 using namespace blink;
 
 static bool supportsUIStateTransitionProgress()
 {
     // FIXME: This is temporary until all platforms that support ScrollbarPainter support this part of the API.
     static bool globalSupportsUIStateTransitionProgress = [NSClassFromString(@"NSScrollerImp") instancesRespondToSelector:@selector(mouseEnteredScroller)];
     return globalSupportsUIStateTransitionProgress;
 }
 
@@ skipping 592 matching lines @@
     [_trackAlphaAnimation.get() invalidate];
     [_uiStateTransitionAnimation.get() invalidate];
     [_expansionTransitionAnimation.get() invalidate];
     END_BLOCK_OBJC_EXCEPTIONS;
 }
 
 @end
 
 namespace blink {
 
-PassOwnPtr<ScrollAnimator> ScrollAnimator::create(ScrollableArea* scrollableArea)
+PassRefPtr<ScrollAnimator> ScrollAnimator::create(ScrollableArea* scrollableArea)
 {
-    return adoptPtr(new ScrollAnimatorMac(scrollableArea));
+    return adoptRef(new ScrollAnimatorMac(scrollableArea));
 }
 
 ScrollAnimatorMac::ScrollAnimatorMac(ScrollableArea* scrollableArea)
     : ScrollAnimator(scrollableArea)
     , m_initialScrollbarPaintTimer(this, &ScrollAnimatorMac::initialScrollbarPaintTimerFired)
     , m_sendContentAreaScrolledTimer(this, &ScrollAnimatorMac::sendContentAreaScrolledTimerFired)
 #if USE(RUBBER_BANDING)
     , m_scrollElasticityController(this)
     , m_snapRubberBandTimer(this, &ScrollAnimatorMac::snapRubberBandTimerFired)
 #endif
@@ skipping 691 matching lines @@
         return;
 
     m_visibleScrollerThumbRect = rectInViewCoordinates;
 }
 
 bool ScrollAnimatorMac::canUseCoordinatedScrollbar() {
     return ScrollbarThemeMacCommon::isOverlayAPIAvailable();
 }
 
 } // namespace blink