To my surprise, this tab was missing, something that I cannot let be! The fix for me was as follows (in this specific order):
- Download & install Code Contracts v1.4.50910.0: http://msdn.microsoft.com/en-US/devlabs/dd491992.aspx
- Reboot the OS.
- Launch VS and open up a project the properties pages. You should now see the 'Code Contracts' tab.
- There's no need to run devenv /setup, as that's done for you via the installer of this version.