View Single Post
OmniFocus exports information in a format that Google Calendar can import, but at the time of this writing, gCal lacks the ability to subscribe to calendars in password-protected locations.

In other words, for this to work, you'd have to sync your OmniFocus database to a un-protected location, making it available to basically anyone on the internet.

I would strongly recommend against that, but if you're willing to do so, you can check the "Publish Due reminders as a calendar" box in OmniFocus' "Sync" preferences, then use the steps from this Google support article to import the resulting .iCal file.

Needless to say, filing a "support password-protected calendar subscriptions" feature request against Google Calendar would be a good idea. :-)