This script applies specifically to blogger templates which have been heavily modified. In this case, we have our own web hosting service. If this is the case with your blog, and you've reached this far in the stages of modification, edit at your own discretion. (See these notes on complete removal and overhaul of Blogger CSS). This step in modification came after removal of some of the main template's CSS and the ability to link to the widget CSS file directly.
You run Google's official Pagespeed test and get a near-failing grade on the CSS on Mobile web sites:
And not the greatest score on the Desktop version:
If you recognize this in your template's modified code:
Then this is what is needed to replace it with:
Here is the score result when testing for Mobile
Here is the score result when testing for Desktop