Named Data Networking (NDN) is a new Internet architecture that replaces today's focus on where - addresses and hosts - with what - the content that users and applications care about. One of NDN's prominent advantages is scalable and efficient content distribution due to its native support of caching and multicast in the network. However, at the last hop to wireless users, often the WiFi link, current NDN implementation still treats the communication as multiple unicast sessions, which will cause duplicate packets and waste of bandwidth when multiple users request for the same popular content. WiFi's built-in broadcast mechanism can alleviate this problem, but it suffers from packet loss since there is no MAC-layer acknowledgement as in unicast. In this paper, we develop a new NDN-based cross-layer approach called NLB for efficient and scalable live video streaming over wireless LAN. The idea is to use WiFi's broadcast channel to deliver content from the access point to the users, a leader-based mechanism to suppress duplicate requests from users, and receiver-driven rate control and loss recovery. The design is implemented and evaluated in a physical testbed comprised of a commodity residential access point and 20 WiFi clients. While NDN with multiple unicast sessions or plain broadcast can support no more than 7 concurrent viewers of a 1Mbps streaming video, NDN plus NLB supports all 20 viewers, and can likely support many more when present.