In follow up to this issue, I found that in
ProfileImpl::GetOffTheRecordProfile( ), it only creates a single incognito
session per regular profile no matter how many incognito windows the user
chooses to open.
I have done experimental changes to this function, which allows the
creating a separate incognito profile per incognito window. After the
experimental change, I am able to log into different accounts with the same
website at the same time in different incognito windows. It looks like at least
the cookies are successfully isolated. The Incognito-session-only preferences
are still shared (are these preferences used by the extensions?) but I am not
sure how critical that is.
I think it might be nice to support multiple incognito
sessions in chrome and it doesn't seem like a daunting task to support it.
It's just a personal suggestion and it's a feature needed only by a small
percentage of users.