HP Stream laptops uses low end CPUs with weak integrated graphics. They are too weak to allow you to play SW: Battlefront. You need to look for a laptop with dedicated graphics to play the game. A $1,500 gaming laptop will certainly let you play SW Battlefront, but $700 - $800 "gaming" laptops will still allow you play the game. Naturally, the CPU and graphics will not be as powerful compared a typical $1,500 gaming laptop so you would need to play on lower settings.
I would recommend just sticking with your HP Stream as your portable computer, but if you really want to play SWB and you have the money, I would buy (or build) a desktop. Its just far more enjoyable and should be cheaper. Just look for a computer with i5 or AMD FX Processor with a Nvidia GTX 750Ti (or higher, Nvidia 950,960,970,980s are really good) or an AMD 270. (again, 280, 280x, 290x, Etc are better).I think a 750Ti can get you to play at medium low @1080p with 60Fps.