I think early innings by Sri Lankan team was good, Pathum Nissanka and Lahiru Udara were making partnership but later Lahiru Udara got out at 29 runs and then Dinesh Chandimal arrived who was playing with strategy and making a partnership.
In the first about 40 overs, Bangladesh were searching for wickets and Taijul Islam took a single wicket. Bangladeshi captain gave him multiple times, till 35 overs he delivered 15 overs out of them while the other bowlers delivered about 6 to 7 overs. However, at that time, they were struggling badly for wickets.
Well at Bangladesh innings I taught they secure things and have a strong position but now Siri Lankan early on innings indicates it's completely batting friendly track and now situation were moving toward draw because it's end of day three and Siri Lankan still have trail to filled while after that they has to set lead for Bangladesh so final results will not be concluded in rest of days. Honestly draw still fine in favor of Bangladesh as they already have some bad stats in recent past at test format. Hope such steps toward positive move will help them to get back confidence for coming tournament and series.
Now I realize why Bangladesh wanted to play the third day as well. This is a good batting pitch and playing longer would make the chances of it being a draw greater. They knew they didn't achieved any spectacular score so they were trying to stretch it longer but Sri Lanka when got the chance to bat knew from start they need to score fast. With Pathum Nissanka's 187, they made a quick 368 without playing the whole day. They would be aiming to score quick tomorrow and lead Bangladesh by 200 something and would rather try to allout Bangladesh than play the whole 4th day.
But in every circumstance, I see this match going towards a draw.