Java Plugin for Chrome on OS X Mountain Lion 10.8.2
You are in luck, Apple released a "fix" for this issue:

http://support.apple.com/kb/HT5559

Basically Apple has provided some terminal commands that move the plug-in from the disabled folder to where it needs to be to work in Chrome.

However you would be better off (read: SAFER!) by using the updated Java plugin from Oracle and a browser that can use that plugin, like Firefox or Safari.