Add ScrollDirectionPhysical enum in Scroll types.

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
    modify it under the terms of the GNU Library General Public
@@ skipping 342 matching lines @@
     virtual GraphicsLayer* layerForScrolling() const override;
     virtual GraphicsLayer* layerForHorizontalScrollbar() const override;
     virtual GraphicsLayer* layerForVerticalScrollbar() const override;
     virtual GraphicsLayer* layerForScrollCorner() const override;
     virtual int scrollSize(ScrollbarOrientation) const override;
     virtual void setScrollOffset(const IntPoint&) override;
     virtual void setScrollOffset(const DoublePoint&) override;
     virtual bool isScrollCornerVisible() const override;
     virtual bool userInputScrollable(ScrollbarOrientation) const override;
     virtual bool shouldPlaceVerticalScrollbarOnLeft() const override;
-    virtual bool scroll(ScrollDirection, ScrollGranularity, float delta = 1) override;
+    virtual bool scroll(ScrollDirectionPhysical, ScrollGranularity, float delta = 1) override;
     virtual LayoutRect scrollIntoView(
         const LayoutRect& rectInContent,
         const ScrollAlignment& alignX,
         const ScrollAlignment& alignY) override;
 
     // The window that hosts the FrameView. The FrameView will communicate scrolls and repaints to the
     // host window in the window's coordinate space.
     HostWindow* hostWindow() const override;
 
     // Returns a clip rect in host window coordinates. Used to clip the blit on a scroll.
@@ skipping 515 matching lines @@
     static const unsigned visualPixelThreshold = 32 * 32;
     if (m_visuallyNonEmptyPixelCount > visualPixelThreshold)
         setIsVisuallyNonEmpty();
 }
 
 DEFINE_TYPE_CASTS(FrameView, Widget, widget, widget->isFrameView(), widget.isFrameView());
 
 } // namespace blink
 
 #endif // FrameView_h