Fix a crasher with the translate infobar....

Fix a crasher with the translate infobar.
Turns out calling Close() from an infobar class to close it is a bad idea
as it only removes its associated view so it is not displayed, but the
tab contents still belives it is showing.
RemoveInfoBar() should be called instead.
I made the InfobarContainer methods private and made InfobarContainer a friend
to prevent other people from running into the same problem.

BUG=47669
TEST=Open a www.google.de In the translate infobar, click Nope. Navigate away
     from the page, it should not crash.


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=51131

[sky, 2010-06-29 00:20:45]

LGTM