This band member of One Direction started out his TV carrier with a cameo in "If I Had You"? 
If I Had You (TV drama):  Future member of One Direction, Louis Tomlinson, makes a blink-and-you'll-miss-it cameo appearance as a member of a group of boys who discover a body in the river. Louis Tomlinson:  Tomlinson began his career as an actor, appearing in ITV drama film "If I Had You" and the BBC drama "Waterloo Road".
Louis Tomlinson