Ensure that data doesn't leak between users on cros chrome crash.

We had a problem where if chrome crashed on cros and was relaunched
it would always run with the Default profile. This meant that two
different users could see the same data...a big problem.
We patched in the OS by deleting the profile directory each time
but this is the right fix.
When the session_manager reruns Chrome on a crash it will now
pass a new flag (--login-user). Chrome uses this and ensures that
the profile dir (specified by --login-profile) is mounted as an
encrypted drive. If this flag isn't specified then Chrome uses the
Default profile, but in incognito mode so no data is written.

BUG=chromiumos:1967
TEST=Login to chromeos as user1, in a terminal kill the browser process, chrome relaunches, log into gmail, sign out (using menu or power button). Login as user2, kill browser process, chrome relaunches, go to gmail. Ensure that user1 isn't logged in.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=42279

[Will Drewry, 2010-03-22 15:34:23]

LGTM

(Nice to see the OTR decision move into the profile manager code)

It's the first time I've looked at that code much so a second set of eyes might
be good.

http://codereview.chromium.org/1094009/diff/1/9
File chrome/browser/profile_manager.cc (right):

http://codereview.chromium.org/1094009/diff/1/9#newcode227
chrome/browser/profile_manager.cc:227:
CHECK(chromeos::CryptohomeLibrary::Get()->IsMounted());
Any API requests for cryptohome are fair game since we still have to rewrite it.
Probably the sooner we move to a nicer API, the less pain it will be tyo change
out the underlying code.

[sky, 2010-03-22 17:04:39]

LGTM

http://codereview.chromium.org/1094009/diff/5001/6008
File chrome/browser/profile_manager.cc (right):

http://codereview.chromium.org/1094009/diff/5001/6008#newcode47
chrome/browser/profile_manager.cc:47: Profile*
ProfileManager::GetDefaultProfile() {
Order of methods in .cc should match that of .h

[DaveMoore, 2010-03-22 22:18:50]

Please take another look. This change was made to get browser and ui tests
passing. They had many tests that couldn't work with the OTR Profile.

[sky, 2010-03-22 22:37:07]

LGTM