I use some hosts file overrides for two reasons:
1) testing at $dayjob
2) to block some spammy things, and if their in-browser resolver did not take those into consideration
If either of those were impacted, it would be bye-bye chrome.
Why did the team deliberate so much?
I will let the readers ponder this.
There are already some very good stub resolvers and resolver libraries available to users (e.g. dnsqr and the djbdns library). I have a hard time believing Google is going to do better than djb.
Of course I have no problem with them or anyone else writing another one. Have at it. The more attention brought to name resolution the better -- because it can be so easily abused for questionable purposes, it is something that deserves user oversight.
But why does Google need to place theirs _inside the browser_? That is a very curious design decision.
Check the comments, there are some very good discussions in there with Daniel Stenberg about c-ares and other resolvers.
I, currently at least, would still prefer that the os handle name resolution.
As Ilya notes, a fuller discussion can be found at the G+ post's comments section.
Note: I'm a Chromium developer on our network stack. I'm also the author of the G+ post linked to in the article.