Danny has a good chin, and seems to be one tough hombre, in fact I think those are his best qualities. Unfortunately I don't think that does him much good against Pacquiao apart from help him take an extended beating.
Khan was touching him a lot, and Danny did great to stay concentrated and stick to his game plan, lots of people would panic taking that much leather in the first few rounds, Garcia didn't. The thing is getting hit by Khan and getting hit by Pacquiao, different ball game. Yes Pacquiao is slower than Khan at this stage, but he is better in almost all other aspects. I actually think Pacquiao has become much harder to hit clean the older he has got, he is a much better defensive fighter today then he was 3-4-5 years ago. This is overlooked by a lot of people.