The following will NPE:
content_shell --enable-slimming-paint-v2 --root-layer-scrolls https://pr.gg

* thread #32: tid = 0x1db373, 0x0000000112f7017f libcc.dylib`cc::draw_property_utils::(anonymous namespace)::CalculateVisibleRects(visible_layer_list=size=1, property_trees=0x000000012b001428, non_root_surfaces_enabled=true) + 1919 at draw_property_utils.cc:401, name = 'Compositor', stop reason = EXC_BAD_ACCESS (code=1, address=0x70)
    frame #0: 0x0000000112f7017f libcc.dylib`cc::draw_property_utils::(anonymous namespace)::CalculateVisibleRects(visible_layer_list=size=1, property_trees=0x000000012b001428, non_root_surfaces_enabled=true) + 1919 at draw_property_utils.cc:401
   398 	    // the viewport clip.
   399 	    const bool fully_visible =
   400 	        !clip_node->layers_are_clipped &&
-> 401 	        !effect_tree.Node(clip_node->target_effect_id)->surface_is_clipped;
   402 	
   403 	    if (fully_visible) {
   404 	      if (!transform_node->ancestors_are_invertible) {

I'm not sure why RLS and non-RLS would differ here. This code was added in:
https://chromium.googlesource.com/chromium/src/+/c3bd281c3071e563de4c19da17cccec9c9770ed6