pos/pos_place/views/templates.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <template id="assets" inherit_id="point_of_sale.assets">
        <xpath expr="." position="inside">
            <script type="text/javascript" src="/pos_place/static/src/js/widget.js"></script>
            <script type="text/javascript" src="/pos_place/static/src/js/chrome.js"></script>
            <script type="text/javascript" src="/pos_place/static/src/js/models.js"></script>
            <script type="text/javascript" src="/pos_place/static/src/js/gui.js"></script>
        </xpath>
    </template>
</odoo>