MainFrame scrollbars should work with RFV instead of FV

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 275 matching lines @@
   bool scrollbarsCanBeActive() const override;
   void scrollbarVisibilityChanged() override;
   IntRect scrollableAreaBoundingBox() const override;
   void registerForAnimation() override;
   void deregisterForAnimation() override;
   bool userInputScrollable(ScrollbarOrientation) const override;
   bool shouldPlaceVerticalScrollbarOnLeft() const override;
   int pageStep(ScrollbarOrientation) const override;
   ScrollBehavior scrollBehaviorStyle() const override;
   CompositorAnimationTimeline* compositorAnimationTimeline() const override;
+  void getTickmarks(Vector<IntRect>& rects) const override;
 
   void visibleSizeChanged();
 
   // FIXME: We shouldn't allow access to m_overflowRect outside this class.
   LayoutRect overflowRect() const { return m_overflowRect; }
 
   void scrollToAbsolutePosition(
       const FloatPoint& position,
       ScrollBehavior scrollBehavior = ScrollBehaviorInstant,
       ScrollType scrollType = ProgrammaticScroll) {
@@ skipping 276 matching lines @@
 
 DEFINE_TYPE_CASTS(PaintLayerScrollableArea,
                   ScrollableArea,
                   scrollableArea,
                   scrollableArea->isPaintLayerScrollableArea(),
                   scrollableArea.isPaintLayerScrollableArea());
 
 }  // namespace blink
 
 #endif  // LayerScrollableArea_h