Remove a bunch of frame-level scrolling machinery.

sky/engine/core/rendering/RenderView.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 60 matching lines @@
     {
         return style()->isHorizontalWritingMode() ? viewWidth(ExcludeScrollbars) : viewHeight(ExcludeScrollbars);
     }
     int viewLogicalHeight() const;
     LayoutUnit viewLogicalHeightForPercentages() const;
 
     float zoomFactor() const;
 
     FrameView* frameView() const { return m_frameView; }
 
-    enum ViewportConstrainedPosition {
-        IsNotFixedPosition,
-        IsFixedPosition,
-    };
-    void mapRectToPaintInvalidationBacking(const RenderLayerModelObject* paintInvalidationContainer, LayoutRect&, ViewportConstrainedPosition, const PaintInvalidationState*) const;
     virtual void mapRectToPaintInvalidationBacking(const RenderLayerModelObject* paintInvalidationContainer, LayoutRect&, const PaintInvalidationState*) const override;
 
     void invalidatePaintForRectangle(const LayoutRect&) const;
 
     void invalidatePaintForViewAndCompositedLayers();
 
     virtual void paint(PaintInfo&, const LayoutPoint&) override;
     virtual void paintBoxDecorationBackground(PaintInfo&, const LayoutPoint&) override;
 
     enum SelectionPaintInvalidationMode { PaintInvalidationNewXOROld, PaintInvalidationNewMinusOld, PaintInvalidationNothing };
@@ skipping 105 matching lines @@
             m_paintInvalidationState->m_cachedOffsetsEnabled = true;
     }
 private:
     const PaintInvalidationState* m_paintInvalidationState;
     bool m_didDisable;
 };
 
 } // namespace blink
 
 #endif // RenderView_h