Remove ScrollableArea::GetFrameViewBase and move ScheduleAnimation into subclasses.

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

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 191 matching lines @@
   IntRect ScrollableAreaBoundingBox() const override;
   bool UserInputScrollable(ScrollbarOrientation) const override { return true; }
   bool ShouldPlaceVerticalScrollbarOnLeft() const override { return false; }
   bool ScrollAnimatorEnabled() const override;
   void ScrollControlWasSetNeedsPaintInvalidation() override {}
   void UpdateScrollOffset(const ScrollOffset&, ScrollType) override;
   GraphicsLayer* LayerForContainer() const override;
   GraphicsLayer* LayerForScrolling() const override;
   GraphicsLayer* LayerForHorizontalScrollbar() const override;
   GraphicsLayer* LayerForVerticalScrollbar() const override;
-  FrameViewBase* GetFrameViewBase() override;
+  bool ScheduleAnimation() override;
   CompositorAnimationHost* GetCompositorAnimationHost() const override;
   CompositorAnimationTimeline* GetCompositorAnimationTimeline() const override;
   IntRect VisibleContentRect(
       IncludeScrollbarsInRect = kExcludeScrollbars) const override;
   RefPtr<WebTaskRunner> GetTimerTaskRunner() const final;
 
   // Visual Viewport API implementation.
   double ScrollLeft();
   double ScrollTop();
   double ClientWidth();
@@ skipping 60 matching lines @@
   float scale_;
   IntSize size_;
   float browser_controls_adjustment_;
   float max_page_scale_;
   bool track_pinch_zoom_stats_for_page_;
 };
 
 }  // namespace blink
 
 #endif  // VisualViewport_h