[1] Defer JavaScript | PageSpeed Module | Google Developers ( 版) <https://developers.google.com/speed/pagespeed/service/DeferJavaScript#limitations>
Defer JavaScript doesn't defer a script tag if it has the data-pagespeed-no-defer attribute (preferred) or pagespeed_no_defer attribute (deprecated). This is useful when a script tag needs to be executed while loading the page. For example, a script tag may be updating the main content dynamically as a slideshow of images in the visible content of the page. Usage:
<script data-pagespeed-no-defer>...</script>
[2] PageSpeedの動作を検証 - apps-gcp ( 版) <http://www.apps-gcp.com/pagespeedverification/>
Defer Javascriptをオンにしつつ、その適用範囲を制限するために、「設定のカスタマイズ」で紹介したような方法で、url-blacklistを指定する他に、以下のようにpagespeed_no_defer属性をscript要素に付け加えるという方法もあるようです。
1
<script pagespeed_no_defer="">…</script>
<script pagespeed_no_defer="">//<![CDATA[
(function(){var g=this,h=function(b,d){var a=b.split("."),c=g;a[0]in c||!c.execScript||c.ex