Fix const correctness of containerForRepaint

Source/core/rendering/RenderLayerRepainter.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 52 matching lines @@
 class RenderLayerRepainter {
     WTF_MAKE_NONCOPYABLE(RenderLayerRepainter);
 public:
     RenderLayerRepainter(RenderLayerModelObject&);
 
     // Return a cached repaint rect, computed relative to the layer renderer's containerForRepaint.
     LayoutRect repaintRect() const { return m_repaintRect; }
     LayoutRect repaintRectIncludingNonCompositingDescendants() const;
 
     void repaintAfterLayout(bool shouldCheckForRepaint);
-    void repaintIncludingNonCompositingDescendants(RenderLayerModelObject* repaintContainer);
+    void repaintIncludingNonCompositingDescendants(const RenderLayerModelObject* repaintContainer);
 
     void setRepaintStatus(RepaintStatus status) { m_repaintStatus = status; }
 
     void computeRepaintRects(const RenderLayerModelObject* repaintContainer);
     void computeRepaintRectsIncludingDescendants();
 
     // Indicate that the layer contents need to be repainted. Only has an effect
     // if layer compositing is being used,
     void setBackingNeedsRepaint();
     void setBackingNeedsRepaintInRect(const LayoutRect&); // r is in the coordinate space of the layer's render object
@@ skipping 11 matching lines @@
 
     unsigned m_repaintStatus; // RepaintStatus
 
     LayoutRect m_repaintRect; // Cached repaint rects. Used by layout.
     LayoutPoint m_offset;
 };
 
 } // namespace WebCore
 
 #endif // RenderLayerRepainter_h