Made session restore block about:flags driven browser restart.

Made session restore block about:flags driven browser restart.

This fixes a regression that's triggered by user password change where subsequent GAIA sign in flow wouldn't preserve OAuth2 refresh token anymore - see the BUG for more details.

BUG=289965
TEST=manual
R=xiyuan@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=225294

[xiyuan, 2013-09-24 23:50:05]

LGTM

[commit-bot: I haz the power, 2013-09-25 01:05:00]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/zelidrag@chromium.org/24473002/7001

[commit-bot: I haz the power, 2013-09-25 06:46:03]

Retried try job too often on linux_chromeos for step(s) unit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_chro...

[commit-bot: I haz the power, 2013-09-25 14:50:45]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/zelidrag@chromium.org/24473002/7001

[commit-bot: I haz the power, 2013-09-25 16:43:15]

Retried try job too often on linux_chromeos for step(s) unit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_chro...

[commit-bot: I haz the power, 2013-09-25 22:44:30]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/zelidrag@chromium.org/24473002/46001

[zel, 2013-09-26 01:11:37]

Committed patchset #4 manually as r225294 (presubmit successful).