Working on this

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d42dfa9205926e4f03bfbbac580799a1d4db80da

commit d42dfa9205926e4f03bfbbac580799a1d4db80da
Author: Sergio Villar Senin <svillar@igalia.com>
Date: Fri Nov 16 11:04:32 2018

Convert OAuth2LoginManager away from SigninManager

Replace the usage of SigninManager API by IdentityManager's.

Bug:  905281 
Change-Id: I64453935c4312eeaf1f42c770aa01d16b6238730
Reviewed-on: https://chromium-review.googlesource.com/c/1337615
Commit-Queue: Sergio Villar <svillar@igalia.com>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608724}
[modify] https://crrev.com/d42dfa9205926e4f03bfbbac580799a1d4db80da/chrome/browser/chromeos/login/signin/oauth2_login_manager.cc

Done