http://software.hixie.ch/utilities/js/live-dom-viewer/saved/679 Generated content doesn't seem to work on <tbody> and <tr> in WebKit. Works fine in Gecko and Opera. The use case for doing this is to insert a block (or table-row) box between <tbody>s to separate them visually without cluttering the markup with spacer <tr>s.
On the referred test case in Comment 0, I am getting "PASS" twice in the rendered view and it matches with all browsers. I think it has been fixed along the way and I think this can be marked as "RESOLVED CONFIGURATION CHANGED". Thanks!