Rework compositor touch hit testing

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 78 matching lines @@
     MainThreadScrollingReasons mainThreadScrollingReasons() const;
     bool shouldUpdateScrollLayerPositionOnMainThread() const { return mainThreadScrollingReasons() != 0; }
 
     void willDestroyScrollableArea(ScrollableArea*);
     void scrollableAreaScrollLayerDidChange(ScrollableArea*);
     void scrollableAreaScrollbarLayerDidChange(ScrollableArea*, ScrollbarOrientation);
     void setLayerIsContainerForFixedPositionLayers(GraphicsLayer*, bool);
     void updateLayerPositionConstraint(RenderLayer*);
     void touchEventTargetRectsDidChange(const Document*);
 
-    void computeAbsoluteTouchEventTargetRects(const Document*, Vector<IntRect>&);
-
     static String mainThreadScrollingReasonsAsText(MainThreadScrollingReasons);
     String mainThreadScrollingReasonsAsText() const;
     Region computeShouldHandleScrollGestureOnMainThreadRegion(const Frame*, const IntPoint& frameLocation) const;
 
+    class TouchEventTargetRectsObserver {
+    public:
+        virtual void touchEventTargetRectsChanged(const LayerHitTestRects&) = 0;
+    };
+
+    void addTouchEventTargetRectsObserver(TouchEventTargetRectsObserver*);
+    void removeTouchEventTargetRectsObserver(TouchEventTargetRectsObserver*);
+
 protected:
     explicit ScrollingCoordinator(Page*);
 
     static GraphicsLayer* scrollLayerForScrollableArea(ScrollableArea*);
     static GraphicsLayer* horizontalScrollbarLayerForScrollableArea(ScrollableArea*);
     static GraphicsLayer* verticalScrollbarLayerForScrollableArea(ScrollableArea*);
 
     unsigned computeCurrentWheelEventHandlerCount();
     GraphicsLayer* scrollLayerForFrameView(FrameView*);
     GraphicsLayer* counterScrollingLayerForFrameView(FrameView*);
 
     Page* m_page;
 
 private:
     void recomputeWheelEventHandlerCountForFrameView(FrameView*);
     void setShouldUpdateScrollLayerPositionOnMainThread(MainThreadScrollingReasons);
 
     bool hasVisibleSlowRepaintViewportConstrainedObjects(FrameView*) const;
     void updateShouldUpdateScrollLayerPositionOnMainThread();
     
     static WebKit::WebLayer* scrollingWebLayerForScrollableArea(ScrollableArea*);
 
     void setShouldHandleScrollGestureOnMainThreadRegion(const Region&);
-    void setTouchEventTargetRects(const Vector<IntRect>&);
+    void setTouchEventTargetRects(const LayerHitTestRects&);
+    void computeTouchEventTargetRects(LayerHitTestRects&);
     void setWheelEventHandlerCount(unsigned);
 
     WebKit::WebScrollbarLayer* addWebScrollbarLayer(ScrollableArea*, ScrollbarOrientation, PassOwnPtr<WebKit::WebScrollbarLayer>);
     WebKit::WebScrollbarLayer* getWebScrollbarLayer(ScrollableArea*, ScrollbarOrientation);
     void removeWebScrollbarLayer(ScrollableArea*, ScrollbarOrientation);
 
     typedef HashMap<ScrollableArea*, OwnPtr<WebKit::WebScrollbarLayer> > ScrollbarMap;
     ScrollbarMap m_horizontalScrollbars;
     ScrollbarMap m_verticalScrollbars;
 
+    HashSet<TouchEventTargetRectsObserver*> m_touchEventTargetRectsObservers;
 };
 
 } // namespace WebCore
 
 #endif // ScrollingCoordinator_h