For Londoners, rain is simply a fact of life. But for Burberry, it’s the inspiration for seemingly endless variations of luxurious outerwear, from the heritage brand’s best-selling trench coat to oversized duffels and fur-lined bombers. The British fashion house showcased its latest designs Monday at London Fashion Week to a soulful Amy Winehouse soundtrack interspersed with a woman’s voice saying “I love London ... the smell of London when it rains.”