Lilia Vu was already smiling when her long, snaking birdie putt dropped into the cup on the 18th green, confirming her — not that it was ever in doubt — as the Women’s British Open champion and a two-time major winner. The 25-year-old Californian has plenty to smile about. A first LPGA Tour win. Two major championships. An imminent ranking of No. 1 in the world.