Get OS X Chrome to accept self-signed SSL certificate for localhost

I've been trying to get this working all day, and I have a strong feeling that my issue is specific to Yosemite. I'm running OS X 10.10.3 on a retina Macbook Pro.

I took instructions from http://www.robpeck.com/2010/10/google-chrome-mac-os-x-and-self-signed-ssl-certificates/

But while that does indeed fix the errors thrown by Safari, it does not fix the issue in chrome. I can "proceed anyways" but the red crossed out lock is not going away. I want to implement a feature in a web app that requires SSL support in Chrome specifically, but I can't test it locally due to this issue.

Does anyone know why this is happening? Or if it's not even possible to do this?

Try enabling the "Allow invalid certificates for resources loaded from localhost" flag in chrome, enter "chrome://flags" in the URL box of chrome, search for "invalid" (part of above flag name), click enable, and restart Chrome.