GitLab

Relanding crrev.com/c/1105772 after crbug.com/855797.
Broken tests caused by calls to GetAccountsForDicePromos
were fixed.

When the user is signed out of Chrome and the profile icon
has not been explicitly changed, AvatarToolbarButton now
uses the account icon of the first sync promo account.

Screenshots:
https://drive.google.com/file/d/1a7kr12KtA11Wt7MQ9MLnSf-M3D9nlLdg/view?usp=sharing
https://drive.google.com/file/d/1nKLnoD1sbcZOvwGQY3YtHVTUv32DQNFn/view?usp=sharing

TBR=droger@chromium.org
TBR=tapted@chromium.org
TBR=bsep@chromium.org

Bug: 853363, 855797
Change-Id: I830aedd32c30cb1c39fc24551dd225c81d62c097
Reviewed-on: https://chromium-review.googlesource.com/1112253
Commit-Queue: Thomas Tangl <tangltom@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Reviewed-by: Thomas Tangl <tangltom@chromium.org>
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570699}