Remove outdated FIXME

Source/core/layout/LayoutObjectChildList.cpp

 /*
  * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 177 matching lines @@
     if (!oldChild.isRooted())
         return;
     if (oldChild.isBody()) {
         oldChild.view()->setShouldDoFullPaintInvalidation();
         return;
     }
 
     DisableCompositingQueryAsserts disabler;
     // FIXME: We should not allow paint invalidation out of paint invalidation state. crbug.com/457415
     DisablePaintInvalidationStateAsserts paintInvalidationAssertDisabler;
-    const LayoutBoxModelObject* paintInvalidationContainer = oldChild.containerForPaintInvalidation();
+    const LayoutBoxModelObject& paintInvalidationContainer = *oldChild.containerForPaintInvalidation();
     oldChild.invalidatePaintUsingContainer(paintInvalidationContainer, oldChild.previousPaintInvalidationRect(), PaintInvalidationLayoutObjectRemoval);
     if (RuntimeEnabledFeatures::slimmingPaintEnabled())
-        oldChild.invalidateDisplayItemClients(*paintInvalidationContainer);
+        oldChild.invalidateDisplayItemClients(paintInvalidationContainer);
 }
 
 } // namespace blink