Revert paint-invalidation-container ASSERT

Source/core/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. 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>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 979 matching lines @@
     return compositedLayer;
 }
 
 RenderLayer* RenderLayer::enclosingLayerForPaintInvalidation() const
 {
     ASSERT(isAllowedToQueryCompositingState());
 
     if (isPaintInvalidationContainer())
         return const_cast<RenderLayer*>(this);
 
-    for (const RenderLayer* curr = parent(); curr; curr = curr->parent()) {
+    for (const RenderLayer* curr = compositingContainer(); curr; curr = curr->compositingContainer()) {
         if (curr->isPaintInvalidationContainer())
             return const_cast<RenderLayer*>(curr);
     }
 
     return 0;
 }
 
 void RenderLayer::setNeedsCompositingInputsUpdate()
 {
     m_needsAncestorDependentCompositingInputsUpdate = true;
@@ skipping 1843 matching lines @@
     }
 }
 
 void showLayerTree(const blink::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif