The Chargers have acquired 27-year old DT Travis Johnson from the Texans for a conditional sixth round pick.  Johnson played in 15 games (14 starts) for the Texans last season and he made 28 tackles, had 1 sack, defensed 2 passes and he forced a fumble.  In four years with the Texans, Johnson played in 54 games (38 starts) in which he made 106 tackles, 2 sacks, defensed 8 passes, forced a fumble and he picked off a pass.  This was a great trade for the Chargers as Johnson should give them a run stopper that they need in the middle of the D.