chromium/content/test/data/accessibility/css/user-select.html

<!--
@BLINK-ALLOW:notUserSelectableStyle*
-->
<div style="user-select:none">1. unselectable </div>
<div style="user-select:text"> 2. Selectable </div>
<div style="user-select:none"> 3. unselectable </div>
<div style="user-select:text"> 4. Selectable </div>
<!-- List bullets are not selectable, but that is not due to user-select, 
    so they will not have the notUserSelectableStyle attribute -->
<ul>
    <li>One</li>
</ul>
<!-- Should inherit -->
<div style="user-select:none">
    <div style="user-select:inherit">Inner</div>
</div>