<!DOCTYPE html>
<style>
  td { border: 5px solid black }
</style>
Should repaint collapsed borders when cells resize.
<table style="width: 300px; border-collapse: collapse">
  <tr>
    <td>A</td><td id="cell" style="width: 200px">B</td><td>C</td>
  </tr>
</table>
<script src="../../../resources/run-after-layout-and-paint.js"></script>