The Chiefs signed free agent wide receiver Devard Darling to a three-year contract on Tuesday.  Financial terms were not released.  Darling posted 18 catches for 326 yards and three touchdowns while playing in all 16 games for Baltimore last season.  He has recorded 20 grabs for 331 yards and three scores to go with two special teams tackles since being drafted by the Ravens in the third round of the 2004 draft.