mail-addons/im_notif/im_notif_views.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <template id="assets_backend" name="im_notif assets" inherit_id="web.assets_backend">
            <xpath expr="." position="inside">
                <!--<link rel="stylesheet" href="/im_notif/static/src/css/im_notif.css"/>-->
                <script type="text/javascript" src="/im_notif/static/src/js/im_notif.js"></script>
            </xpath>
        </template>

    </data>
</openerp>