Snap has long been known as the maker of Snapchat, an app that sends disappearing messages, photographs and videos. But over the past few years, the company has repositioned itself as a modern-day camera company. One of the products that Snap has worked on to bolster that direction is a drone, according to three people briefed on the project who asked to remain anonymous because the details are confidential. A drone could help Snap’s users take overhead videos and photographs, and then feed that visual data to the company.