I believe that all of the 777 on AF have a few bassinet hook ups in economy. Did you look up the specific aircraft for that flight on the AF site?
http://www.airfrance.us/US/en/common...lan_cabine.htm
The baby bottle signifies the bassinet (cradle) spots. We flew a AF 777, but in business, with our 11 month old and used one of the bassinets. We ended up only having him in it for a short period of time, but it made for a great spot to store all the baby stuff while in the bulkhead.
Depending on the length of the layover, you could also look in to getting a day use room at a hotel. I know there is a Sheraton located inside the CDG airport. On a trip last year to Prague, we had a 6 hour layover in CDG and booked a room for my wife, I, and our 3 year old to rest in after the flight from MSP. I'm sure there's something similar in LHR. We used points for the booking too, which really made it worthwhile.