Here's the brand where it is working: https://github.com/jwulf/publican-redhat-video/


A breakdown of how it works:

Javascript files are found here: https://github.com/jwulf/publican-redhat-video/tree/master/en-US/scripts

Inject the javascript into the book html through xsl (there's some schema.org metadata thrown in there as a bonus)
[from https://github.com/jwulf/publican-redhat-video/blob/master/xsl/html-single.xsl]:

<!-- set the onload of the page -->
<!-- http://www.sagehill.net/docbookxsl/BodyAtts.html -->
<xsl:template name="body.attributes">
    <xsl:attribute name="onLoad">skynetBookLoad()</xsl:attribute>
    <xsl:attribute name="itemscope"/>
    <xsl:attribute name="itemtype">http://schema.org/TechArticle</xsl:attribute>
</xsl:template>

<xsl:template name="user.header.content">
    <meta itemprop="aboutProduct">
        <xsl:attribute name="content">
        <xsl:value-of select="concat(//productname[1], ' ', //productnumber[1])"/>
        </xsl:attribute>
    </meta>
</xsl:template>

<!-- inject our javascript into the footer -->
<!-- http://www.sagehill.net/docbookxsl/InsertExtHtml.html -->
<!-- Inject a div.skynetBookID with Product_Name/Book_Name
  This is used for cookies for the book -->
<xsl:template name="user.footer.content">
    <div class="skynetBookID"><xsl:value-of select="//productname[1]"/>/<xsl:value-of select="//title[1]"/>/<xsl:value-of select="//productnumber[1]"/></div>
    <xsl:choose>
        <xsl:when test="$embedtoc != 0">
        <!-- web path -->

        <script type="text/javascript">
            <xsl:attribute name="src">
                <xsl:value-of select="concat($tocpath, '/../', $brand, '/', $langpath, '/scripts/jquery-1.4.2.min.js')"/>
            </xsl:attribute>
        </script>

        <script type="text/javascript">
            <xsl:attribute name="src">
                <xsl:value-of select="concat($tocpath, '/../', $brand, '/', $langpath, '/scripts/utils.js')"/>
            </xsl:attribute>
        </script>

        <script type="text/javascript">
            <xsl:attribute name="src">
                <xsl:value-of select="concat($tocpath, '/../', $brand, '/', $langpath, '/scripts/code-lang-switcher.js')"/>
            </xsl:attribute>
        </script>

        <script type="text/javascript">
            <xsl:attribute name="src">
                <xsl:value-of select="concat($tocpath, '/../', $brand, '/', $langpath, '/scripts/changelogs.js')"/>
            </xsl:attribute>
        </script>
      
        <script type="text/javascript">
            <xsl:attribute name="src">
                <xsl:value-of select="concat($tocpath, '/../', $brand, '/', $langpath, '/scripts/skynet-book.js')"/>
            </xsl:attribute>
        </script>
    </xsl:when>
    <xsl:otherwise>
        <!-- desktop path -->
        <script type="text/javascript">
            <xsl:attribute name="src">Common_Content/scripts/jquery-1.4.2.min.js</xsl:attribute>
        </script>
        <script type="text/javascript">
            <xsl:attribute name="src">Common_Content/scripts/utils.js</xsl:attribute>
        </script>
        <script type="text/javascript">
            <xsl:attribute name="src">Common_Content/scripts/code-lang-switcher.js</xsl:attribute>
        </script>
        <script type="text/javascript">
            <xsl:attribute name="src">Common_Content/scripts/changelogs.js</xsl:attribute>
        </script>
        <script type="text/javascript">
            <xsl:attribute name="src">Common_Content/scripts/skynet-book.js</xsl:attribute>
        </script>
        </xsl:otherwise>
    </xsl:choose>
</xsl:template>