CompleteConnect method completes a connection to another pin.
Pointer to the other pin's IPin interface.
This method is called on both pins at the end of the connection process. The connecting pin calls it from within the CBasePin::Connect method, and the receiving pin calls it from within the CBasePin::ReceiveConnection method.
In the base class, this method simply returns S_OK. If a derived class has any requirements for completing a connection, it should override this method. For example, the CBaseOutputPin class uses this method to decide the memory allocator.
If this method fails, the overall connection attempt also fails, and the pin disconnects from the receiving pin.