When Johnny Depp was first cast as Tonto in Disney and Jerry Bruckheimer’s bigscreen adaptation of “The Lone Ranger,” Armie Hammer was a relative unknown in Hollywood who was ready to break out as Batman in Warner Bros.’ “Justice League.”Three years later, Hammer has been handed a high-profile black mask he’ll actually get to wear, landing the titular role as the crime-fighting Texas Ranger in “Lone Ranger.” Thesp is finalizing a deal to saddle up and shout the signature “Hi-yo, Silver! Away!” line in the pic that Gore Verbinski will shoot sometime in the fall based on a script by Justin Haythe. Since “Justice League” was jettisoned because of the WGA strike and for creative reasons, Hammer came to be known instead for his role as the Winklevoss twins in Sony’s “The Social Network.” He recently landed a gig as the prince in Relativity Media’s “The Brothers Grimm: Snow White” (Julia Roberts will play the evil queen) and recently wrapped a supporting role, alongside Leonardo DiCaprio, in Clint Eastwood’s J. Edgar Hoover biopic for Warner Bros. and Imagine Entertainment. Hammer had been the frontrunner for the “Lone Ranger” role for weeks, but casting now moves the project forward, making it Bruckheimer’s next tentpole after the fourth “Pirates of the Caribbean” pic sets sail this weekend. Production would start after Depp wraps up WB’s “Dark Shadows” adaptation and Hammer finishes “Snow White.” Bruckheimer and Disney have long been eager to get “Lone Ranger” on the bigscreen. Depp has been attached as Tonto since 2008, when the thesp took the Kodak Theater’s stage, backed by the USC marching band playing the show’s theme song, during a Disney showcase of upcoming films. Depp, at the time, was dressed as Captain Jack Sparrow and wore the Lone Ranger’s black mask. (That move confused attendees, making them think Depp would play the titular hero. But Depp will play the Ranger’s trusty Indian co-hort, instead, who calls the masked man, “Kemo Sabe.”) Bruckheimer has already been promoting “Lone Ranger” on his shingle’s website with a logo for the pic that Disney has not yet dated. It could bow as early as fall 2012. “Lone Ranger” galloped into pop culture back in 1933 as a radio show before turning into a TV series during the 1950s and spinning off into movies and comicbooks. In 2003, the WB starred Chad Michael Murray (“One Tree Hill”) as the masked man in a TV movie that served as a backdoor pilot, but it didn’t go anywhere.