remove-details-in-exec-command-crash.html

<!DOCTYPE html>
<script>
if (window.testRunner)
    testRunner.dumpAsText();
document.addEventListener("DOMSubtreeModified", function() {
});
function selectstart() {
  var oElement = event.srcElement;
  oElement.insertAdjacentHTML('afterbegin', '<details></details>')
  oElement.innerText = 'Test passes if it does not crash.';
}
document.addEventListener("selectstart", selectstart);
window.onload = function(){
  document.execCommand("SelectAll")
};
</script>

chromium/third_party/blink/web_tests/dom/mutation-event-tests/fast/dom/shadow/remove-details-in-exec-command-crash.html