Revert of Remove OneClickSigninHelper since it is no longer used. (patchset #5 id:340001 of https://codereview.chromium.org/
914363003/)
Reason for revert:
Broke the tab_switching.tough_energy_cases benchmark on the perf bots.
BUG=465692
Original issue's description:
> Remove OneClickSigninHelper since it is no longer used.
>
> BUG=260022,350202
>
> Committed: https://crrev.com/
be592667bdf919fb8292c88c1b59767add856ba4
> Cr-Commit-Position: refs/heads/master@{#319662}
TBR=noms@chromium.org,asvitkine@chromium.org,sky@chromium.org,rogerta@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=260022,350202
Review URL: https://codereview.chromium.org/
998513002
Cr-Commit-Position: refs/heads/master@{#319862}