Remove assumption that null containerForRepaint assumes RenderView

Source/core/rendering/compositing/RenderLayerCompositor.cpp

 /*
  * Copyright (C) 2009, 2010 Apple Inc. 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 765 matching lines @@
         applyUpdateLayerCompositingStateChickenEggHacks(layer, compositedLayerUpdate);
 }
 
 void RenderLayerCompositor::repaintOnCompositingChange(RenderLayer* layer)
 {
     // If the renderer is not attached yet, no need to repaint.
     if (layer->renderer() != &m_renderView && !layer->renderer()->parent())
         return;
 
     RenderLayerModelObject* repaintContainer = layer->renderer()->containerForRepaint();
-    // FIXME: Repaint container should never be null. crbug.com/363699
-    if (!repaintContainer)
-        repaintContainer = &m_renderView;
-
+    ASSERT(repaintContainer);
     layer->repainter().repaintIncludingNonCompositingDescendants(repaintContainer);
 }
 
 // This method assumes that layout is up-to-date, unlike repaintOnCompositingChange().
 void RenderLayerCompositor::repaintInCompositedAncestor(RenderLayer* layer, const LayoutRect& rect)
 {
     RenderLayer* compositedAncestor = layer->enclosingCompositingLayerForRepaint(ExcludeSelf);
     if (!compositedAncestor)
         return;
     ASSERT(compositedAncestor->compositingState() == PaintsIntoOwnBacking || compositedAncestor->compositingState() == PaintsIntoGroupedBacking);
@@ skipping 917 matching lines @@
     } else if (graphicsLayer == m_scrollLayer.get()) {
         name = "LocalFrame Scrolling Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore