Implement CSSOM Smooth Scroll API

Source/platform/scroll/ScrollView.h

 /*
  * Copyright (C) 2004, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Holger Hans Peter Freyther
  *
  * 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
@@ skipping 142 matching lines @@
     IntPoint adjustScrollPositionWithinRange(const IntPoint&) const;
     int scrollX() const { return scrollPosition().x(); }
     int scrollY() const { return scrollPosition().y(); }
 
     virtual IntSize overhangAmount() const OVERRIDE;
 
     void cacheCurrentScrollPosition() { m_cachedScrollPosition = scrollPosition(); }
     IntPoint cachedScrollPosition() const { return m_cachedScrollPosition; }
 
     // Functions for scrolling the view.
-    virtual void setScrollPosition(const IntPoint&);
-    void scrollBy(const IntSize& s) { return setScrollPosition(scrollPosition() + s); }
+    virtual void setScrollPosition(const IntPoint&, ScrollBehavior = ScrollBehaviorInstant);
+    void scrollBy(const IntSize& s, ScrollBehavior behavior = ScrollBehaviorInstant)
+    {
+        return setScrollPosition(scrollPosition() + s, behavior);
+    }
 
     bool scroll(ScrollDirection, ScrollGranularity);
 
     // Scroll the actual contents of the view (either blitting or invalidating as needed).
     void scrollContents(const IntSize& scrollDelta);
 
     // This gives us a means of blocking painting on our scrollbars until the first layout has occurred.
     void setScrollbarsSuppressed(bool suppressed, bool repaintOnUnsuppress = false);
     bool scrollbarsSuppressed() const { return m_scrollbarsSuppressed; }
 
@@ skipping 159 matching lines @@
     void updateOverhangAreas();
 
     virtual int pageStep(ScrollbarOrientation) const OVERRIDE;
 }; // class ScrollView
 
 DEFINE_TYPE_CASTS(ScrollView, Widget, widget, widget->isScrollView(), widget.isScrollView());
 
 } // namespace WebCore
 
 #endif // ScrollView_h