This shailo has come to the Beis Horah many times by R' Shammai Gross and haven't been able to find anyone yet that speaks about it (although perhaps the psak is obvious?)
It says in Shulchan Aruch that if someone rents a dira the chiyuv of putting Mezuzos on the dira is on them. Many times here in Eretz Yisrael (as I'm sure in other places) it's become the custom that the Landlord puts the mezuzos on the dira. Especially in a case when it's a dira being rented as "fully furnished" apartment. While there might be some discussion in this I know R' Shammai holds this to be the "minhag" that such a dira also comes with mezuzos. However in a situation when this is the first tenant the dira is being rented to and it doesn't yet have mezuzos up and the bal dira wants to put up before the tenant comes in can he make a bracha? If the tenant had already made some sort of kinyan and made him a shliach to put them up I would say for sure then he could make a bracha. However if he didn't make him a shliach can the landlord still put up with a bracha?