LayoutTests/fast/text/break-word-pre-wrap.html

<style>
div { position:relative; white-space:pre-wrap; overflow-wrap: break-word; border:1px solid blue; font-family:ahem; }
</style>
<div style="width:4ex">xxxx   x</div>
<div style="width:5ex">xxxx   x</div>
<div style="width:6ex">xxxx   x</div>