Move ScrollableArea timer to TaskRunnerTimer.

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 415 matching lines @@
   bool shouldPerformScrollAnchoring() const override;
   ScrollAnchor* scrollAnchor() override { return &m_scrollAnchor; }
   bool isPaintLayerScrollableArea() const override { return true; }
 
   LayoutBox* layoutBox() const override { return &box(); }
 
   FloatQuad localToVisibleContentQuad(const FloatQuad&,
                                       const LayoutObject*,
                                       unsigned = 0) const final;
 
+  RefPtr<WebTaskRunner> getTimerTaskRunner() const final;
+
   bool shouldRebuildHorizontalScrollbarLayer() const {
     return m_rebuildHorizontalScrollbarLayer;
   }
   bool shouldRebuildVerticalScrollbarLayer() const {
     return m_rebuildVerticalScrollbarLayer;
   }
   void resetRebuildScrollbarLayerFlags();
 
   // Did DelayScrollOffsetClampScope prevent us from running
   // clampScrollOffsetsAfterLayout() in updateAfterLayout()?
@@ skipping 153 matching lines @@
 
 DEFINE_TYPE_CASTS(PaintLayerScrollableArea,
                   ScrollableArea,
                   scrollableArea,
                   scrollableArea->isPaintLayerScrollableArea(),
                   scrollableArea.isPaintLayerScrollableArea());
 
 }  // namespace blink
 
 #endif  // LayerScrollableArea_h