Move convertViewportToWindow and convertWindowToViewport from

third_party/WebKit/Source/platform/scroll/ScrollableArea.h

 /*
  * Copyright (C) 2008, 2011 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 42 matching lines @@
 class Widget;
 
 enum IncludeScrollbarsInRect {
     ExcludeScrollbars,
     IncludeScrollbars,
 };
 
 class PLATFORM_EXPORT ScrollableArea : public GarbageCollectedMixin {
     WTF_MAKE_NONCOPYABLE(ScrollableArea);
 public:
-    static int pixelsPerLineStep(HostWindow*);
+    static int pixelsPerLineStep(HostWindow*, Widget*);

[dcheng, 2016/09/08 05:25:47]

Oh... I guess it's because of this. So I guess we need to move the frame tree /
WebWidgetClient into public/platform first.

[lfg, 2016/09/08 21:40:43]

Acknowledged.

     static float minFractionToStepWhenPaging();
     static int maxOverlapBetweenPages();
 
     // Convert a non-finite scroll value (Infinity, -Infinity, NaN) to 0 as
     // per http://dev.w3.org/csswg/cssom-view/#normalize-non_finite-values.
     static double normalizeNonFiniteScroll(double value) { return std::isfinite(value) ? value : 0.0; }
 
     // The window that hosts the ScrollableArea. The ScrollableArea will communicate scrolls and repaints to the
     // host window in the window's coordinate space.
     virtual HostWindow* getHostWindow() const { return 0; }
@@ skipping 211 matching lines @@
     // Need to promptly let go of owned animator objects.
     EAGERLY_FINALIZE();
     DECLARE_VIRTUAL_TRACE();
 
     virtual void clearScrollAnimators();
 
 protected:
     ScrollableArea();
 
     ScrollbarOrientation scrollbarOrientationFromDirection(ScrollDirectionPhysical) const;
-    float scrollStep(ScrollGranularity, ScrollbarOrientation) const;
+    float scrollStep(ScrollGranularity, ScrollbarOrientation);
 
     void setScrollOrigin(const IntPoint&);
     void resetScrollOriginChanged() { m_scrollOriginChanged = false; }
 
     // Needed to let the animators call scrollPositionChanged.
     friend class ScrollAnimatorCompositorCoordinator;
     void scrollPositionChanged(const DoublePoint&, ScrollType);
 
     bool horizontalScrollbarNeedsPaintInvalidation() const { return m_horizontalScrollbarNeedsPaintInvalidation; }
     bool verticalScrollbarNeedsPaintInvalidation() const { return m_verticalScrollbarNeedsPaintInvalidation; }
     bool scrollCornerNeedsPaintInvalidation() const { return m_scrollCornerNeedsPaintInvalidation; }
     void clearNeedsPaintInvalidationForScrollControls()
     {
         m_horizontalScrollbarNeedsPaintInvalidation = false;
         m_verticalScrollbarNeedsPaintInvalidation = false;
         m_scrollCornerNeedsPaintInvalidation = false;
     }
 
 private:
     void programmaticScrollHelper(const DoublePoint&, ScrollBehavior);
     void userScrollHelper(const DoublePoint&, ScrollBehavior);
 
     // This function should be overriden by subclasses to perform the actual scroll of the content.
     virtual void setScrollOffset(const DoublePoint& offset, ScrollType) = 0;
 
-    virtual int lineStep(ScrollbarOrientation) const;
+    virtual int lineStep(ScrollbarOrientation);
     virtual int pageStep(ScrollbarOrientation) const;
     virtual int documentStep(ScrollbarOrientation) const;
     virtual float pixelStep(ScrollbarOrientation) const;
 
     mutable Member<ScrollAnimatorBase> m_scrollAnimator;
     mutable Member<ProgrammaticScrollAnimator> m_programmaticScrollAnimator;
 
     unsigned m_scrollbarOverlayStyle : 2; // ScrollbarOverlayStyle
 
     unsigned m_scrollOriginChanged : 1;
@@ skipping 10 matching lines @@
     // vertical-lr / ltr            NO                      NO
     // vertical-lr / rtl            NO                      YES
     // vertical-rl / ltr            YES                     NO
     // vertical-rl / rtl            YES                     YES
     IntPoint m_scrollOrigin;
 };
 
 } // namespace blink
 
 #endif // ScrollableArea_h