Remove ScrollableArea::GetFrameViewBase and move ScheduleAnimation into subclasses.

third_party/WebKit/Source/core/frame/FrameView.h

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@kde.org)
    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights
    reserved.
 
    This library is free software; you can redistribute it and/or
@@ skipping 433 matching lines @@
   PaintLayer* Layer() const override;
   GraphicsLayer* LayerForScrolling() const override;
   GraphicsLayer* LayerForHorizontalScrollbar() const override;
   GraphicsLayer* LayerForVerticalScrollbar() const override;
   GraphicsLayer* LayerForScrollCorner() const override;
   int ScrollSize(ScrollbarOrientation) const override;
   bool IsScrollCornerVisible() const override;
   bool UpdateAfterCompositingChange() override;
   bool UserInputScrollable(ScrollbarOrientation) const override;
   bool ShouldPlaceVerticalScrollbarOnLeft() const override;
-  FrameViewBase* GetFrameViewBase() override;
+  bool ScheduleAnimation() override;
   CompositorAnimationHost* GetCompositorAnimationHost() const override;
   CompositorAnimationTimeline* GetCompositorAnimationTimeline() const override;
   LayoutBox* GetLayoutBox() const override;
   FloatQuad LocalToVisibleContentQuad(const FloatQuad&,
                                       const LayoutObject*,
                                       unsigned = 0) const final;
   RefPtr<WebTaskRunner> GetTimerTaskRunner() const final;
 
   LayoutRect ScrollIntoView(const LayoutRect& rect_in_content,
                             const ScrollAlignment& align_x,
@@ skipping 806 matching lines @@
                   frameViewBase.IsFrameView());
 DEFINE_TYPE_CASTS(FrameView,
                   ScrollableArea,
                   scrollableArea,
                   scrollableArea->IsFrameView(),
                   scrollableArea.IsFrameView());
 
 }  // namespace blink
 
 #endif  // FrameView_h