e8e8d245bc
Unfortunately, this change does not make `white-spaces-after-execCommand-insertparagraph.tentative.html` pass because the insert paragraph handler inserts a temporary `<br>` element and that causes normalizing the following white-spaces at the split point. However, Chrome does not normalize the following white-spaces if it begins with an NBSP. Differential Revision: https://phabricator.services.mozilla.com/D239465