<html>
<style>
  object {
    border-top-left-radius: 0;
  }
</style>
<script>
  onload = () => {
    if (window.testRunner)
        testRunner.dumpAsText()

    document.styleSheets[0].insertRule(`object { border-radius: inherit; }`);
    document.execCommand('SelectAll');
    document.execCommand('Copy');
  };
</script>
<object></object>

<p>Test passes if it does not crash</p>
</html>