Question: Who replaced Robert Downey Jr. for the male lead role in the film Gravity?
About the article "Gravity (film)", section "Development".

Candidate passages:
"Gravity" is a 2013 3D science-fiction thriller and space drama film directed, co-written, co-produced and co-edited by Alfonso Cuarón.
The film stars Sandra Bullock and George Clooney as astronauts involved in the mid-orbit destruction of a space shuttle and their attempt to return to Earth.
Cuarón wrote the screenplay with his son Jonás and attempted to develop the project at Universal Studios.
After the rights to the project were sold, the project found traction at Warner Bros. instead.
The studio approached multiple actresses before casting Bullock in the female lead role.
Robert Downey Jr. was also involved as the male lead before leaving the project and being replaced by Clooney.
"Gravity" opened at the 70th Venice International Film Festival in August 2013.
Its North American premiere was three days later at the Telluride Film Festival.
It received a wide release in the United States and Canada on October 4, 2013.
The film was met with universal acclaim from critics and audiences alike; both groups giving praise for Emmanuel Lubezki's cinematography, Steven Price's musical score, Cuarón's direction, and Bullock's performance.
The film received ten nominations at the 86th Academy Awards, the most nominations of 2014's ceremony tied with "American Hustle".
The nominations includes Best Picture, Best Director for Cuarón, Best Actress for Bullock, and Best Original Score for Price, among others.
Alfonso Cuarón won the Golden Globe Award for Best Director, and the film was further nominated for Best Motion Picture – Drama, Best Actress in Drama for Bullock and Best Original Score.
It received eleven nominations at the 67th British Academy Film Awards, more than any other film of 2013, including Best Film, Outstanding British Film, Best Director, Best Original Screenplay, and Best Actress in a Leading Role.
Including his nominations as producer (for Best Film awards) and editor, Cuarón was also the person with the most nominations, with five overall. 
Alfonso Cuarón wrote the screenplay with his son Jonás.
Cuarón told "Wired" magazine, "I watched the Gregory Peck movie "Marooned" over and over as a kid."
That film is about the first crew of an experimental space station returning to Earth in an Apollo capsule that suffers a thruster malfunction.
Cuarón attempted to develop his project at Universal Pictures, where it stayed in development for several years.
After the rights to the project were sold, the project began development at Warner Bros, who acquired the project.
In February 2010, it attracted the attention of Angelina Jolie, who had rejected a sequel to "Wanted".
Later in the month, she rejected "Wanted 2", partially because the studio did not want to pay the fee she had received for her latest two movies and because she wanted to direct her Bosnian war film "In the Land of Blood and Honey".
In March, Robert Downey, Jr. entered talks to be cast in the male lead role.
In mid-2010, Marion Cotillard tested for the female lead role.
By August 2010, Scarlett Johansson and Blake Lively were in the running for the role.
In September, Cuarón received approval from Warner Bros. to offer the role without a screen test to Natalie Portman, who was being praised for her performance in the recently released "Black Swan".
Portman rejected the project because of scheduling conflicts and Warner Bros. then approached Sandra Bullock for the role.
In November 2010, Downey left the project to star in "How to Talk to Girls"a project in development with Shawn Levy attached to direct.
The following December, with Bullock signed for the co-lead role, George Clooney replaced Downey.
The problem of shooting long scenes in a zero-g environment was a challenge.
Eventually, the team decided to use computer-generated imagery for the spacewalk scenes and automotive robots to move Bullock's character for interior space station scenes.
This meant that shots and blocking had to be planned well in advance for the robots to be programmed.
It also made the production period much longer than expected.
When the script was finished, Cuarón assumed it would take about a year to complete the film, but it took four and a half years.
In the 2008 film Iron Man (2008 film), the title character wears an armor made from a titanium-gold alloy.
According to actor Robert Downey Jr., who played the role of Iron Man, the suit fit him "like a gold-titanium glove". 
Team Downey is an American production company founded by Robert Downey, Jr. and Susan Downey that produces film and television properties.
David Gambino is the president of production.
Team Downey is based at Warner Bros. 
Chafed Elbows is a 1966 film directed by Robert Downey, Sr. A manic comic parody made for $12,000, "Chafed Elbows" was a commercial success that raised the flag of the underground film scene and elevated the good cause of bad taste.
Downey photographed most of the movie with a still 35mm camera and had the film processed at Walgreens drugstore.
These pictures were animated alongside a few live-action scenes and almost all the dialogue was dubbed to rather hilarious effect.
One scene was even shot in Anthology Film Archives’s upstairs theater back in the days when the building was still a defunct downtown courthouse.
An ingenious comedy with a rare visual sensibility, comic-book playfulness and cheeky bad attitude.
All 13 of the female roles were played by Elsie Downey, Robert Downey's wife, and the lead male role by George Morgan.