Great posts over at HogwartsProffesor on the transformations in Deathly Hallows. Here's what I write about Harry:

One of the major transformation is Harry himself when he discovers that Severus Snape was the bravest man he’s ever known. We remember when Harry hurled the accusation of “Coward!” at Snape after Dumbledore’s death on the Tower and Harry is pursuing Snape across the Hogwarts grounds. Snape just about looses it then and now we know why. Harry hated him, hated him with a personal hatred that in some ways was even deeper than his hatred of Voldemort. Harry could not remember how Voldemort had killed his parents, he has what he’s been told. But Harry had witnessed Snape’s actions against Dumbledore, coming after his own six years of being humiliated by Snape at Hogwarts.

Where does that compassion come from when Harry kneels by Snape who lays dying. This should have been a moment of triumph for Harry - seeing Snape die and not by his own hand. But we have a very different scene, where Harry’s first response is pity and even obedience, looking into Snape’s eyes not yet knowing that what Snape wanted to look on as his last act was the eyes of the woman he loved.

It isn’t until he sees Snape’s memories that he truly understands and the transformation in Harry is so profound he names his eldest son not only after Dumbledore, but after Snape as well.