Revert 219146 "[sync] Force re-auth during sync setup if Oauth2 ..."

Revert 219146 "[sync] Force re-auth during sync setup if Oauth2 ..."

> [sync] Force re-auth during sync setup if Oauth2 token is unavailable
> 
> If an enterprise user disables sync via a dashboard clear, and goes on
> to re-enable sync at a later time, set up can fail due to an expired or
> missing Oauth2 token.
> 
> This patch updates SyncSetupHandler::OpenSyncSetup to first check if an
> auth token is available for sync, and if not, force a re-auth.
> 
> R=atwilson
> TBR=fgorski,rogerta
> BUG=276650
> TEST=Disable sync for an enterprise user, exit chrome, delete "Web
> Data*" from the profile dir, restart chrome, and set up sync. Re-auth
> must be forced in this case.
> 
> Review URL: https://chromiumcodereview.appspot.com/23005016

TBR=rsimha@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=221035

[sail, 2013-09-03 21:55:58]

Committed patchset #1 manually as r221035.

[Raghu Simha, 2013-09-03 22:17:45]

LGTM based on comments in bug 278543.