The Browns were making their first trip to San Diego since 2006.  The game was back and forth, with neither team leading by more than one possession.  The Chargers led 7-3 after the 1st quarter.  On the Browns' first drive of the second quarter, QB Josh McCown threw a 34-yard touchdown pass to RB Duke Johnson to put the Browns up 10-7.  The teams traded field goals, making it a 13-13 game at halftime.  The Browns scored a field goal at the start of the 3rd quarter to go up 16-13.  On the Chargers' next drive, QB Philip Rivers led the Chargers to a touchdown, going up 20-16 heading into the 4th quarter.  After K Travis Coons kicked a field goal to cut the deficit to 20-19, Rivers led another touchdown drive to put the Chargers up 27-19.  On the Browns' next drive, they reached the end zone, assisted by an incredible catch by TE Gary Barnidge on the Chargers' 1 yard line.  They converted on the two point conversion to tie the game at 27-27 with just over 2 minutes remaining.  The Chargers reached the Browns' 24 yard line with under 50 seconds to play.  The Browns began to use timeouts until the Chargers faced 4th down with 2 seconds to play.  After the Chargers called timeout, their kicker had an opportunity to win the game with a 39-yard field goal.  The 39 yard game winning attempt was off to the right, and the game appeared to be on its way to overtime..  However, CB Tramon Williams was flagged for being offside during the play, giving the Chargers another attempt, this time from 34 yards.  The field goal was converted, and the Chargers won 30-27.  The Browns committed 12 penalties in the game, including this critical offside penalty.
Question: Which penalty led to the Chargers second FG attempt?
Answer: offside