Implement CSSOM smooth scroll for Elements

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 271 matching lines @@
     bool isTrackingPaintInvalidations() const { return m_isTrackingPaintInvalidations; }
     void resetTrackedPaintInvalidations();
 
     String trackedPaintInvalidationRectsAsText() const;
 
     typedef HashSet<ScrollableArea*> ScrollableAreaSet;
     void addScrollableArea(ScrollableArea*);
     void removeScrollableArea(ScrollableArea*);
     const ScrollableAreaSet* scrollableAreas() const { return m_scrollableAreas.get(); }
 
+    void addAnimatingScrollableArea(ScrollableArea*);
+    void removeAnimatingScrollableArea(ScrollableArea*);
+    const ScrollableAreaSet* animatingScrollableAreas() const { return m_animatingScrollableAreas.get(); }
+
     // With CSS style "resize:" enabled, a little resizer handle will appear at the bottom
     // right of the object. We keep track of these resizer areas for checking if touches
     // (implemented using Scroll gesture) are targeting the resizer.
     typedef HashSet<RenderBox*> ResizerAreaSet;
     void addResizerArea(RenderBox&);
     void removeResizerArea(RenderBox&);
     const ResizerAreaSet* resizerAreas() const { return m_resizerAreas.get(); }
 
     // This function exists for ports that need to handle wheel events manually.
     // On Mac WebKit1 the underlying NSScrollView just does the scrolling, but on most other platforms
@@ skipping 439 matching lines @@
     unsigned m_visuallyNonEmptyPixelCount;
     bool m_isVisuallyNonEmpty;
     bool m_firstVisuallyNonEmptyLayoutCallbackPending;
 
     RefPtrWillBeMember<Node> m_maintainScrollPositionAnchor;
 
     // Renderer to hold our custom scroll corner.
     RawPtrWillBeMember<RenderScrollbarPart> m_scrollCorner;
 
     OwnPtr<ScrollableAreaSet> m_scrollableAreas;
+    OwnPtr<ScrollableAreaSet> m_animatingScrollableAreas;
     OwnPtr<ResizerAreaSet> m_resizerAreas;
     OwnPtr<ViewportConstrainedObjectSet> m_viewportConstrainedObjects;
     OwnPtrWillBeMember<FrameViewAutoSizeInfo> m_autoSizeInfo;
 
     float m_visibleContentScaleFactor;
     IntSize m_inputEventsOffsetForEmulation;
     float m_inputEventsScaleFactorForEmulation;
 
     IntSize m_layoutSize;
     bool m_layoutSizeFixedToFrameSize;
@@ skipping 84 matching lines @@
     }
 
 private:
     RawPtrWillBeMember<FrameView> m_view;
     bool m_originalValue;
 };
 
 } // namespace blink
 
 #endif // FrameView_h