Mac: Delete now-dead elastic overscroll code

Source/platform/scroll/ScrollableArea.h

Index: Source/platform/scroll/ScrollableArea.h
diff --git a/Source/platform/scroll/ScrollableArea.h b/Source/platform/scroll/ScrollableArea.h
index b73c6f78ce5d340f021b56065fefec8f558af04b..e657812dc73e84a8b2ff676d0d7c03b94d585679 100644
--- a/Source/platform/scroll/ScrollableArea.h
+++ b/Source/platform/scroll/ScrollableArea.h
@@ -84,12 +84,6 @@ public:
     bool constrainsScrollingToContentEdge() const { return m_constrainsScrollingToContentEdge; }
     void setConstrainsScrollingToContentEdge(bool constrainsScrollingToContentEdge) { m_constrainsScrollingToContentEdge = constrainsScrollingToContentEdge; }
 
-    void setVerticalScrollElasticity(ScrollElasticity scrollElasticity) { m_verticalScrollElasticity = scrollElasticity; }
-    ScrollElasticity verticalScrollElasticity() const { return static_cast<ScrollElasticity>(m_verticalScrollElasticity); }
-
-    void setHorizontalScrollElasticity(ScrollElasticity scrollElasticity) { m_horizontalScrollElasticity = scrollElasticity; }
-    ScrollElasticity horizontalScrollElasticity() const { return static_cast<ScrollElasticity>(m_horizontalScrollElasticity); }
-
     void setHasViewportConstrainedObjectsForScrollCompensation(bool hasViewportConstrainedObjects) { m_hasViewportConstrainedObjectsForScrollCompensation = hasViewportConstrainedObjects; }
     bool hasViewportConstrainedObjectsForScrollCompensation() const { return m_hasViewportConstrainedObjectsForScrollCompensation; }
 
@@ -199,9 +193,6 @@ public:
     // Returns the bounding box of this scrollable area, in the coordinate system of the enclosing scroll view.
     virtual IntRect scrollableAreaBoundingBox() const = 0;
 
-    virtual bool isRubberBandInProgress() const { return false; }
-    virtual bool rubberBandingOnCompositorThread() const { return false; }
-
     virtual bool scrollAnimatorEnabled() const { return false; }
 
     // NOTE: Only called from Internals for testing.
@@ -316,9 +307,6 @@ private:
 
     unsigned m_inLiveResize : 1;
 
-    unsigned m_verticalScrollElasticity : 2; // ScrollElasticity
-    unsigned m_horizontalScrollElasticity : 2; // ScrollElasticity
-
     unsigned m_scrollbarOverlayStyle : 2; // ScrollbarOverlayStyle
 
     unsigned m_scrollOriginChanged : 1;