TROON, Scotland – On a course adjacent an airport, a 30-year-old golfer from San Diego seemed to leave the ground Sunday and commence gliding above as if oblivious to the fray below. His back nine, so artful and tranquil, felt almost as though he had used the runway just behind No. 10 to start floating overhead like one of those lazy-day planes, the engine barely audible but its hum clearly untouchable. In a callous sport with a furious week of weather, the clear winner wound up looking downright pristine.