Steps as of Chrome v91 (6/17/2021):
- Click the Not secure warning next to the URL
- Click Site settings on the popup box
- Near the bottom of the list is Insecure content, change this to Allow
- Close settings, go back to the site, and Refresh the page
Older Chrome Versions:
timmmy_42 answers this on: https://productforums.google.com/forum/#!topic/chrome/OrwppKWbKnc
In the address bar at the right end should be a ‘shield’ icon, you can
click on that to run insecure content.
This worked for me in Chromium-dev Version 36.0.1933.0 (262849).