WASHINGTON — The House on Wednesday passed a bill that would lead to a nationwide ban of the popular video app TikTok if its China-based owner doesn’t sell, as lawmakers acted on concerns that the company’s current ownership structure is a national security threat.The bill, passed by a vote of 352-65, now goes to the Senate, where its prospects are unclear.TikTok, which has more than 150 million American users, is a wholly owned subsidiary of Chinese technology firm ByteDance Ltd.The lawmakers contend …