Though a grant is not actually delivered into the possession of the grantee, it is considered constructively delivered in the following cases:
(1) when the instrument is, by the agreement of the parties at the time of execution, understood to be delivered and under circumstances that the grantee is entitled to immediate delivery; or
(2) when it is delivered to a stranger for the benefit of the grantee and the grantee's assent is shown or may be presumed.