Remove mainthread overhang painting code

Source/core/paint/FramePainter.h

Index: Source/core/paint/FramePainter.h
diff --git a/Source/core/paint/FramePainter.h b/Source/core/paint/FramePainter.h
index be125640d61b3e2b4022553a7db0e7e8d5183f6f..cb7904d3e69c9311bec8fbbbbd6ad5f7fa1b4340 100644
--- a/Source/core/paint/FramePainter.h
+++ b/Source/core/paint/FramePainter.h
@@ -23,9 +23,6 @@ public:
 
 private:
     void paintScrollbar(GraphicsContext*, Scrollbar*, const IntRect&);
-    void paintOverhangAreas(GraphicsContext*, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect);
-    void calculateAndPaintOverhangAreas(GraphicsContext*, const IntRect& dirtyRect);
-    void paintOverhangAreasInternal(GraphicsContext*, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect);
 
     FrameView& m_frameView;
     static bool s_inPaintContents;