I've upgraded FBSDK in my app to the recent version to support iOS9 and included all the LSApplicationQueriesSchemes schemes and NSAppTransportSecurity. Everything works fine including login and sharing.
But when I try to perform a share, the device brings up a sharing dialog, which is a SLComposeView whereas the simulator pops up the safari from the bottom to show a native facebook dialog. I am really not sure whats causing this difference in the share dialog. Is there something i am missing. Login dialog works fine as expected (Safari popup in both simulator and device). I'm attaching pics for understanding. 
Answering my own question.
I fixed the problem by subclassing the native FBSDKShareButton. Now the behavior looks fine.