By Mark Lamport-Stokes PACIFIC PALISADES, California, Feb 19 (Reuters) - A year after losing a playoff for the Northern Trust Open, long-hitting American Dustin Johnson was back in contention for the title as he moved into a share of the early second-round lead on Friday. Johnson, a nine-times winner on the PGA Tour, took advantage of good scoring conditions at a sun-splashed Riviera Country Club, firing a five-under 66 for an eight-under total of 134. Americans Kyle Reifers (68) and Justin Leonard (69), and Australian Adam Scott (68), were at six under while world number one Jordan Spieth was destined to miss the cut by a big margin after following his opening 79 with a 68. More...