WIP CL in https://chromium-review.googlesource.com/c/chromium/src/+/1298994

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bb012abfe8bf1ea39b0e2cf5115849cafb78ab0a

commit bb012abfe8bf1ea39b0e2cf5115849cafb78ab0a
Author: Antonio Gomes <tonikitoo@igalia.com>
Date: Mon Nov 26 23:41:21 2018

[s13n] Convert arc_auth_service.cc to use IdentityManager

CL also partially needed to touch bits on signin_ui_util.cc|h
and people_handler.cc, both files properly listed on the BUG=
line below.

BUG= 907486 , 898810 , 890796 

Change-Id: Ic0d39cb14e100ae10375f66ca51fd526f3b2d64a
Reviewed-on: https://chromium-review.googlesource.com/c/1348674
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Yury Khmel <khmel@chromium.org>
Commit-Queue: Antonio Gomes <tonikitoo@igalia.com>
Cr-Commit-Position: refs/heads/master@{#610979}
[modify] https://crrev.com/bb012abfe8bf1ea39b0e2cf5115849cafb78ab0a/chrome/browser/chromeos/arc/auth/arc_auth_service.cc
[modify] https://crrev.com/bb012abfe8bf1ea39b0e2cf5115849cafb78ab0a/chrome/browser/signin/signin_ui_util.cc
[modify] https://crrev.com/bb012abfe8bf1ea39b0e2cf5115849cafb78ab0a/chrome/browser/signin/signin_ui_util.h
[modify] https://crrev.com/bb012abfe8bf1ea39b0e2cf5115849cafb78ab0a/chrome/browser/ui/webui/settings/people_handler.cc

This class also uses PO2TS to revoke and update credentials. This should be ported to AccountsMutator (see blocking bug).

Finally, the unittest should be ported away from using PO2TS in favor of using the relevant utilities in identity_test_utils.h.

@blundell Thanks for the comment.  crbug.com/907901  is already on my radar, will probably work on that one once I finish working on a valid CL for 890796, unless someone else beats me to it.

@mario: Thanks! That would be a great one to work on next as I just filed a bunch of bugs that are blocked on it.

@blundell: Quick heads up -> Updated the CL1298994 to include the latest changes and now  crbug.com/907901  is effectively the last stepping stone on our way to migrate people_handler.cc, so I'll be working on that one next.

 Issue 890809  has been merged into this issue.

 Issue 920236  has been merged into this issue.

 Issue 920237  has been merged into this issue.

 Issue 921445  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cacfd35f4e09cbbd969a2c882f3db0eccc127bc0

commit cacfd35f4e09cbbd969a2c882f3db0eccc127bc0
Author: Mario Sanchez Prada <mario@igalia.com>
Date: Wed Jan 16 10:36:33 2019

Migrate PeopleHandler to the IdentityManager

Use the APIs from IdentityManager and PrimaryAccountsMutator to migrate
calls previously depending on SigninManager and ProfileOAuth2TokenService.

Bug:  898810 ,  920236 ,  920237 ,  921445 
Change-Id: I22b046bae82e2539d165d95573c27d47affa6a06
Reviewed-on: https://chromium-review.googlesource.com/c/1298994
Commit-Queue: Mario Sanchez Prada <mario@igalia.com>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623185}
[modify] https://crrev.com/cacfd35f4e09cbbd969a2c882f3db0eccc127bc0/chrome/browser/ui/webui/settings/people_handler.cc
[modify] https://crrev.com/cacfd35f4e09cbbd969a2c882f3db0eccc127bc0/chrome/browser/ui/webui/settings/people_handler_unittest.cc