A Hollywood film yet again finds itself responding to a social-media outcry over the casting of a white actor in a role that was originally Asian-American. British actor Ed Skrein earlier this week joined the cast of the “Hellboy” reboot “Rise of the Blood Queen,” which is to be the third film in the comic adaptation franchise previously helmed by Guillermo del Toro. The character, Ben Daimio, is Japanese-American in Mike Mignola’s “Hellboy” comics and his heritage is central to his backstory. Daimio’s grandmother was a Japanese Imperial assassin in World War II. Many objected to the role not going...