Kevin Spacey (as Jack Abramoff) wears Ray-Ban Aviator sunglasses in the movie Casino Jack. The glasses are clearly the brown/gunmetal frame / brown gradient lenses, but the size seems to be smaller than the Large aviator and might be the 3044 model (smaller Aviator), but we can't find the 3044 in this color combination. A similar version as in the movie is available on Amazon. See also other links to Ray-Ban 3025 Aviator sunglasses below.
The Ray-Ban 3025 are available in many frame and lens colours, including Polarized lenses (which are more expensive but provide better protection for your eyes).
Reference: Ray-Ban RB 3025 Aviator, brown frame/ brown gradient lenses.