Fix const correctness of containerForRepaint

Source/core/rendering/LayoutRepainter.h

Index: Source/core/rendering/LayoutRepainter.h
diff --git a/Source/core/rendering/LayoutRepainter.h b/Source/core/rendering/LayoutRepainter.h
index b23d28965f9e9a2be6c02b1ca472751dfd50cb99..8fac05545165ce1604e9bcb8fb0f738b43e4d79b 100644
--- a/Source/core/rendering/LayoutRepainter.h
+++ b/Source/core/rendering/LayoutRepainter.h
@@ -35,7 +35,7 @@ class RenderObject;
 
 class LayoutRepainter {
 public:
-    LayoutRepainter(RenderObject&, bool checkForRepaint);
+    LayoutRepainter(const RenderObject&, bool checkForRepaint);
 
     bool checkForRepaint() const { return m_checkForRepaint; }
 
@@ -43,8 +43,8 @@ public:
     bool repaintAfterLayout();
 
 private:
-    RenderObject& m_object;
-    RenderLayerModelObject* m_repaintContainer;
+    const RenderObject& m_object;
+    const RenderLayerModelObject* m_repaintContainer;
     // We store these values as LayoutRects, but the final invalidations will be pixel snapped
     LayoutRect m_oldBounds;
     LayoutPoint m_oldOffset;