I found this bug: http://code.google.com/p/chromium/issues/detail?id=580#c69 stating that Chromium doesn't support LiveConnect.
One of the developers responded with
We don't ever intend to support LiveConnect in Chrome. The newest version of the Java plugin from Sun removes the need for this, since it uses NPRuntime to allow scripting.
Does anyone know how to make calls to/from java applets and javascript using the NPAPI / NPRuntime interface? Just a simple example or resource would suffice.