IssueTracker

Summary:

Loading of https://www.google-analytics.com/analytics.js to a website leads to pollute global namespace with an unexpected variable: 'sa'.

Expected Behavior:

analytics.js shouldn't pollute global namespace with a variable that is not, at least, prefixed with 'ga' or 'google'.
Usage of 'ga' or 'google' prefix is already being done with other variables, such as 'gaData', 'gaGlobal', 'gaplugins', 'google_tag_data', 'GoogleAnalyticsObject'

Steps to Reproduce:

1. Add JavaScript tracking snippet to a simple index.html
<!-- Google Analytics -->
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');

ga('create', 'UA-XXXXX-Y', 'auto');
ga('send', 'pageview');
</script>
<!-- End Google Analytics -->

2. Open index.html with a browser

3. Open the DevTools Console

4. Write `window.sa` and hit enter


I added some screenshots that may help you to find where this assignment happens inside analytics.js and a screenshot from my DevTools Console.