What do Protestant churches teach about the fate of deceased infants?

My question is posed to the Protestant churches that teach that man is saved by faith alone. If a person is saved by faith alone, what happens to children who die before they are able to conceive of the meaning of Christ's death and their own need for him and therefore cannot have a saving faith in his work? I heard the John Calvin taught that unbaptized infants were saved by their parents' faith. I've also heard that some Calvinist pastors will say that there is no way of knowing, because God has chosen which will go to heaven and hell apart from human action. Some Roman Catholic teachers taught that there was a place in Hell (or between Heaven and Hell) called limbo for unbaptized infants, but I see that Pope Francis has stated that unbaptized infants do have hope of salvation (http://www.telegraph.co.uk/news/worldnews/1549439/The-Pope-ends-state-of-limbo-after-800-years.html) . But I'm looking for an overview of the positions that are taught as doctrine in the Protestant churches, or are at least in writing from their leaders.