chromium/third_party/blink/web_tests/editing/inserting/5803706-1.html

<div id="description">This tests to make sure that hitting return at the end of a header element breaks out of it. Below, a regular paragraph element should follow the h2.</div>
<div id="edit" contentEditable="true"><h2 id="h2">foo</h2></div>

<script>
if (window.testRunner)
    testRunner.dumpAsText();
h2 = document.getElementById("h2");
text = h2.firstChild;
window.getSelection().collapse(text, text.length);
document.execCommand("InsertParagraph");
if (window.testRunner)
    document.body.innerText = document.getElementById("description").innerText + "\n\n" + document.getElementById("edit").innerHTML;
</script>