Remove assumption that null containerForRepaint assumes RenderView

Source/core/rendering/compositing/RenderLayerCompositor.cpp

Index: Source/core/rendering/compositing/RenderLayerCompositor.cpp
diff --git a/Source/core/rendering/compositing/RenderLayerCompositor.cpp b/Source/core/rendering/compositing/RenderLayerCompositor.cpp
index 010177cafe05a58b58976e9b57a56a6e213156e3..bb8cd74c68e8dfae4ebce528c24fd6dc99b0ebe3 100644
--- a/Source/core/rendering/compositing/RenderLayerCompositor.cpp
+++ b/Source/core/rendering/compositing/RenderLayerCompositor.cpp
@@ -783,10 +783,7 @@ void RenderLayerCompositor::repaintOnCompositingChange(RenderLayer* layer)
         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);
 }