I'm relying on custom mime types in firefox for my company's internal website. Using custom mime types allows me to set up each user's browser to launch an external application when a download of mime type XXX is requested. I can't seem to create this custom mime type in Chrome - at least, I've not found where I can do it.

Any ideas?

Thanks.

A thing to try is the following:

visit /home/username/.config/google-chrome

In that directory a number of files and directories are present, but none seem to have a direct link to mime types.

Within the directory above, the directory Default contains a file named Preferences. Perhaps you can expiriment with that file cause it also contains overrides and global user settings.

The system settings are stored in /etc/default/google-chrome but no mime types are used there.

At my Debian system Chrome also created a directory /opt/google with the file xdg-settings in it, where mime types also are mentioned.

I hope this information is of use for you.