AMP for WordPress が更新されていた．
暫く気付かず…
html_start.php
<head>
<!-- ... -->
<script async custom-element="amp-auto-ads" src="https://cdn.ampproject.org/v0/amp-auto-ads-0.1.js" > </script>
<script async custom-element="amp-analytics" src="https://cdn.ampproject.org/v0/amp-analytics-0.1.js"> </script>
<script async custom-element="amp-iframe" src="https://cdn.ampproject.org/v0/amp-iframe-0.1.js" > </script>
</head>
<body class="<?php echo esc_attr( $this->get( 'body_class' ) ); ?>">
<amp-auto-ads type="adsense"
data-ad-client="ca-pub-????????????????">
</amp-auto-ads>
<amp-analytics type="googleanalytics">
<script type="application/json">
{
"vars": {
"account": "UA-????????-?"
},
"triggers": {
"trackPageview": {
"on": "visible",
"request": "pageview"
}
}
}
</script>
</amp-analytics>
html_end.php
<div style="text-align: center;">
<amp-iframe src='//itl.mydns.jp/f_index.html' sandbox="allow-scripts" width='250px' height='250px'> </amp-iframe>
</div>
</body>
</html>