Fix const correctness of containerForRepaint

Source/core/rendering/RenderSelectionInfo.h

Index: Source/core/rendering/RenderSelectionInfo.h
diff --git a/Source/core/rendering/RenderSelectionInfo.h b/Source/core/rendering/RenderSelectionInfo.h
index b5a1bad5fcb1df2b6ec90864397a5ddd6c1e23dd..da73ebe03ad68319d2d1e7dcdea66cdc4b795077 100644
--- a/Source/core/rendering/RenderSelectionInfo.h
+++ b/Source/core/rendering/RenderSelectionInfo.h
@@ -48,12 +48,12 @@ public:
     }
 
     RenderObject* object() const { return m_object; }
-    RenderLayerModelObject* repaintContainer() const { return m_repaintContainer; }
+    const RenderLayerModelObject* repaintContainer() const { return m_repaintContainer; }
     RenderObject::SelectionState state() const { return m_state; }
 
 protected:
     RenderObject* m_object;
-    RenderLayerModelObject* m_repaintContainer;
+    const RenderLayerModelObject* m_repaintContainer;
     RenderObject::SelectionState m_state;
 };