Move scroll event handlers from layer to layer tree view.

third_party/WebKit/Source/core/page/scrolling/ScrollingCoordinator.h

 /*
  * Copyright (C) 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 58 matching lines @@
     // Return whether this scrolling coordinator handles scrolling for the given frame view.
     bool coordinatesScrollingForFrameView(FrameView*) const;
 
     // Called when any frame has done its layout or compositing has changed.
     void notifyGeometryChanged();
     // Called when any frame recalculates its overflows after style change.
     void notifyOverflowUpdated();
 
     void updateAfterCompositingChangeIfNeeded();
 
-    void updateHaveScrollEventHandlers();
-
     // Should be called whenever a scrollable area is added or removed, or gains/loses a composited layer.
     void scrollableAreasDidChange();
 
     // Should be called whenever the slow repaint objects counter changes between zero and one.
     void frameViewHasBackgroundAttachmentFixedObjectsDidChange(FrameView*);
 
     // Should be called whenever the set of fixed objects changes.
     void frameViewFixedObjectsDidChange(FrameView*);
 
     // Should be called whenever the root layer for the given frame view changes.
@@ skipping 69 matching lines @@
     ScrollbarMap m_verticalScrollbars;
     HashSet<const PaintLayer*> m_layersWithTouchRects;
     bool m_wasFrameScrollable;
 
     MainThreadScrollingReasons m_lastMainThreadScrollingReasons;
 };
 
 } // namespace blink
 
 #endif // ScrollingCoordinator_h