The videotape obtained by TMZ.com shows Brolin on a sidewalk with his arm around Wright when an officer pepper sprays him in the face.
Soon after, both actors are handcuffed and on the ground face down, and it appears in the grainy footage that an officer may be tazering Wright.
Brolin, Wright and five others were charged with interfering with police during a bar brawl.
Prosecutors agreed today to dismiss all charges against the actors and the other defendants if they are not arrested again before March 11.
"These arrests should never have happened," defense attorney Blair Berk told TMZ.com. "Thankfully the prosecution was able to see that and dismiss all charges."