Let's see, I am looking at Sri Lanka as stronger, they should try to bat first if they win the toss and after making about 350, declaring the innings would be a good option to finish the game with the result. All speculations until the real action begins 
I would actually give Bangladesh the advantage in the second test primarily because of Shanto who is in epic form these days. If their bowlers step up properly, they could win this one pretty comfortably.Sri Lanka is struggling on their own turf and that itself says a lot. Gone are the days when they were a legendary side with players like Vaas, Murali, Sanga etc.
If we just look at the score then I think Sri Lankan team are in a better position at the end of day 01. Najmul Hossain Shanto who is the in-form player failed to make runs in this innings and this may be the reason the Bangladesh batting collapsed and they are in a struggling mode. Mushfiqur Rahim and Litton Das did tried to help the team but they also got out in their 30's. They had their eye in and it was expected that they could have played longer but it didn't happened. Both were dismissed by Dinusha and Bangladesh hopes went further down.
I think the fate of this test now depends on how the Sri Lankan team bat in their innings. If they get a good lead, Bangladesh would never be able to recover.