For some reason bug was not automatically updated.

CL http://crrev.com/2704383006 was landed

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7b108ffe5ed8ba43eeb472fc4a20a567a0cebb2b

commit 7b108ffe5ed8ba43eeb472fc4a20a567a0cebb2b
Author: khmel <khmel@chromium.org>
Date: Tue Mar 07 15:55:41 2017

[Merge M57] arc: Handle metrics for Auth operations.

This handles messages with Auth operation metrics and add it to
UMA.

TEST=Locally, new metrics appear in chrome://histograms
BUG=b/35707115
BUG= 695542 

TBR=dcheng@chromium.org,lhchavez@chromium.org,isherman@chromium.org
NOTRY=true
NOPRESUBMIT=true

Approval at b/35707115

Review-Url: https://codereview.chromium.org/2704383006
Cr-Commit-Position: refs/heads/master@{#452722}
(cherry picked from commit 052c11832f70f11fb220abb005bcf93143d2e4e8)

Review-Url: https://codereview.chromium.org/2734983002
Cr-Commit-Position: refs/branch-heads/2987@{#784}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}

[modify] https://crrev.com/7b108ffe5ed8ba43eeb472fc4a20a567a0cebb2b/chrome/browser/chromeos/arc/arc_auth_service.cc
[modify] https://crrev.com/7b108ffe5ed8ba43eeb472fc4a20a567a0cebb2b/chrome/browser/chromeos/arc/arc_auth_service.h
[modify] https://crrev.com/7b108ffe5ed8ba43eeb472fc4a20a567a0cebb2b/chrome/browser/chromeos/arc/arc_optin_uma.cc
[modify] https://crrev.com/7b108ffe5ed8ba43eeb472fc4a20a567a0cebb2b/chrome/browser/chromeos/arc/arc_optin_uma.h
[modify] https://crrev.com/7b108ffe5ed8ba43eeb472fc4a20a567a0cebb2b/components/arc/common/auth.mojom
[modify] https://crrev.com/7b108ffe5ed8ba43eeb472fc4a20a567a0cebb2b/tools/metrics/histograms/histograms.xml

Merge approval is in b/35707115

Verified on build 9202.60.0