I know for Droid Run a streak is activating 3 in a row. For activating/deactivating an uplink in Walker Assault I'm pretty sure it's only 2, same for Turning Point/Supremacy. As for Drop Zone, it's either 2 or 3, I can't remember. I'd say 2 though, since they take longer to capture than droids. Dying doesn't count against any of these streaks, so long as they all happen in 1 round.
