I\'m working on a page close enough to the one in google samples https://developers.google.com/maps/documentation/javascript/examples/places-autocomplete-addressform and it work
I came across this post while trying to solve for a similar use case (populating the Autocomplete with the last place a user searched for).
As far as I can tell it is not possible to set a default for the Autocomplete that it recognises as a place. However, I think you can simulate this effect using the Autocomplete Service (example - also see the reference sections on #AutocompletePrediction and #PlacesService):
This gives your user the impression that the Autocomplete is in use. If the result is what they need, great! If they want to search for a different place set up your autocomplete to listen for place_changed and run autocomplete.getPlace() followed by the same callback.