1. Chrome is the only major browser not to support the Do Not Track header. Google is also the browser vendor whose bottom line would be most impacted if users could easily opt out of tracking. Coincidence?
While I welcome folks from the Chrome team to weigh in on the reasons for this, my own understanding is that adoption of this feature is being blocked by Google's Mountain View based policy team, and is not a decision that is in the hands of engineers.
Compare this to Chrome's absolutely spectacular record in the area of security, where folks like Adam Langley and Chris Evans have been able to ship innovative features that haven't worked their way through the standards process. Examples include HTTPS certificate pinning (that recently led to the discovery of MiTM attacks against Iranian users using the DigiNotar certs).
In the area of security, Chrome's engineers deploy whatever they think will help users. In the area of privacy, Google's lawyers and lobbyists are calling the shots.
(Also, there still isn't a working API to let others support DNT in Chrome. An API exists, I think, but it is quite buggy, AFAIK)
2. Blocking 3rd party cookies by default. Apple defaults to blocking 3rd party cookies, Chrome does not. Both are derived the same webkit core (yes, I know there is different code now), but when Google decided to create Chrome, they went with a different default than the one that Apple had already used -- one that hasn't led to websites breaking for Apple users.
Again, which browser vendors' bottom line would suffer if Chrome users could not easily be tracked? Google.
Let me be clear - I don't think that Chrome is engaging in any sneaky shenanigans to directly track users. No, that would be too obvious. Instead, Chrome just makes it easy for Google's other services to track users, when they stick with the deaults.