It's part of a hardening process that has been employed by weapon smiths for time immemorial, known as "quenching". After you form the laptop case / sword / rifle barrel, and it is still hot, it is to be submerged in urine. I'm surprised it's taken laptop manufacturers so long to catch up.
One of their questions years back was "why does the House of Lords smell like wee?"
Supposedly it at least used to because stale human urine used to be used in the manufacture of Harris Tweed, which used to be the favoured cloth for suits worn by the peers. Which was not usually a problem, except, supposedly, when it rains, at which point the suit would smell faintly of urine. Gather a few hundred of them together in a room...
Here's a thread from the QI forum regarding the topic - the whole thread is quite amusing, but the end contains a fuller description, with their sources:
http://old.qi.com/talk/viewtopic.php?t=1694&start=0&sid=5efc...