If you work with HTTPS connections on your localhost development environment, you will often get an un-secure notification from Chrome, and this will be getting annoying.
To disable those notifications in Chrome type this in your address bar:
Allow invalid certificates for resources loaded from localhost.
and click on "Enable". Done!
As a precaution: You should use separate browsers for personal use and another for development. I do development in Chromium and my regular browsing in Safari.