The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d6ea165b0d47b5442e7b87cbb0b0fd1006f2a115

commit d6ea165b0d47b5442e7b87cbb0b0fd1006f2a115
Author: yusukes <yusukes@chromium.org>
Date: Fri May 26 23:26:04 2017

ARC: Add BootType parameter to ReportBootProgress() in metrics.mojom

ARC has 3 different boot mode. Previously, ARC boot time was recorded
with the same UMA metric like Arc.AndroidBootTime regardless of the
boot mode. This CL allows Chrome to use a dedicated UMA metric for
each boot mode. This is better because a typical boot time is
different for each boot mode.

BUG= 726346 
TEST=tested with opt-in, ota, and regular ARC boot

Review-Url: https://codereview.chromium.org/2906503003
Cr-Commit-Position: refs/heads/master@{#475184}

[modify] https://crrev.com/d6ea165b0d47b5442e7b87cbb0b0fd1006f2a115/components/arc/common/metrics.mojom
[modify] https://crrev.com/d6ea165b0d47b5442e7b87cbb0b0fd1006f2a115/components/arc/metrics/arc_metrics_service.cc
[modify] https://crrev.com/d6ea165b0d47b5442e7b87cbb0b0fd1006f2a115/components/arc/metrics/arc_metrics_service.h
[modify] https://crrev.com/d6ea165b0d47b5442e7b87cbb0b0fd1006f2a115/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b331ebbfd338d17f2b640f3828399cb8f3b3937d

commit b331ebbfd338d17f2b640f3828399cb8f3b3937d
Author: yusukes <yusukes@chromium.org>
Date: Fri Jun 02 15:02:51 2017

Remove backward-compatibility code from ArcMetricService

The fallback code is for M60's container. M61 doesn't require the
code.

BUG= 726346 
TEST=try

Change-Id: I3cb6a34c47e0a763c3517142cb1cc69952076ff0
Reviewed-on: https://chromium-review.googlesource.com/517963
Reviewed-by: Luis Hector Chavez <lhchavez@chromium.org>
Commit-Queue: Yusuke Sato <yusukes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#476650}
[modify] https://crrev.com/b331ebbfd338d17f2b640f3828399cb8f3b3937d/components/arc/metrics/arc_metrics_service.cc

+josafat
I'd like to merge https://chromium.googlesource.com/chromium/src.git/+/d6ea165b0d47b5442e7b87cbb0b0fd1006f2a115 into M60 Chromium for better UMA metrics. The CL has been live in canary channel since 9609.0.0, and only affects ARC++ enabled Chrome OS devices. Please take a look.

Your change meets the bar and is auto-approved for M60. Please go ahead and merge the CL to branch 3112 manually. Please contact milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), josafat@(ChromeOS), bustamante@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ac00b8e7bda9ddd4b081d30d92104f48b62662f8

commit ac00b8e7bda9ddd4b081d30d92104f48b62662f8
Author: yusukes <yusukes@chromium.org>
Date: Mon Jun 05 18:36:21 2017

ARC: Add BootType parameter to ReportBootProgress() in metrics.mojom

ARC has 3 different boot mode. Previously, ARC boot time was recorded
with the same UMA metric like Arc.AndroidBootTime regardless of the
boot mode. This CL allows Chrome to use a dedicated UMA metric for
each boot mode. This is better because a typical boot time is
different for each boot mode.

BUG= 726346 
TEST=tested with opt-in, ota, and regular ARC boot

Review-Url: https://codereview.chromium.org/2906503003
Cr-Original-Commit-Position: refs/heads/master@{#475184}
Review-Url: https://codereview.chromium.org/2918413002 .
Cr-Commit-Position: refs/branch-heads/3112@{#162}
Cr-Branched-From: b6460e24cf59f429d69de255538d0fc7a425ccf9-refs/heads/master@{#474897}

[modify] https://crrev.com/ac00b8e7bda9ddd4b081d30d92104f48b62662f8/components/arc/common/metrics.mojom
[modify] https://crrev.com/ac00b8e7bda9ddd4b081d30d92104f48b62662f8/components/arc/metrics/arc_metrics_service.cc
[modify] https://crrev.com/ac00b8e7bda9ddd4b081d30d92104f48b62662f8/components/arc/metrics/arc_metrics_service.h
[modify] https://crrev.com/ac00b8e7bda9ddd4b081d30d92104f48b62662f8/tools/metrics/histograms/histograms.xml