What if Facebook just becomes TikTok? We may find out soon.

So many social media apps. What if we just ... combined a few? Matteo Della Torre/NurPhoto via Getty Images Facebook is going to start testing a version of the app that just gives users a steady stream of full-screen videos. That is: It's going to try turning itself into TikTok. It's just a test! And "classic" Facebook isn't going away. But this is where everything is headed. Facebook helped make TikTok huge by showing its users tons of ads for the Chinese video company. Now Facebook may end…