Move scroll event handlers from layer to layer tree view.

third_party/WebKit/public/platform/WebLayerTreeView.h

 /*
  * Copyright (C) 2011 Google 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
@@ skipping 125 matching lines @@
         const WebLayer* innerViewportScrollLayer,
         const WebLayer* outerViewportScrollLayer) { }
     virtual void clearViewportLayers() { }
 
     // Used to update the active selection bounds.
     virtual void registerSelection(const WebSelection&) { }
     virtual void clearSelection() { }
 
     // Input properties ---------------------------------------------------
     virtual void setHaveWheelEventHandlers(bool) { };
+    virtual void setHaveScrollEventHandlers(bool) { };
 
     // Debugging / dangerous ---------------------------------------------
 
     virtual bool haveWheelEventHandlers() const { return false; };
+    virtual bool haveScrollEventHandlers() const { return false; };
 
     virtual int layerTreeId() const { return 0; }
 
     // Toggles the FPS counter in the HUD layer
     virtual void setShowFPSCounter(bool) { }
 
     // Toggles the paint rects in the HUD layer
     virtual void setShowPaintRects(bool) { }
 
     // Toggles the debug borders on layers
     virtual void setShowDebugBorders(bool) { }
 
     // Toggles scroll bottleneck rects on the HUD layer
     virtual void setShowScrollBottleneckRects(bool) { }
 };
 
 } // namespace blink
 
 #endif // WebLayerTreeView_h