Additionally it would be good to know how many users have started the migration after attempting to run an android app.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b75aa7267969141e12f5ece554be20d81d39b044

commit b75aa7267969141e12f5ece554be20d81d39b044
Author: fukino <fukino@chromium.org>
Date: Sat Apr 29 15:17:21 2017

cros: Add UMA metrics in encryption migration UI.

Some metrics about encryption migration are already recorded in cryptohomed.
In this CL, I'd like to add following UI-related UMA metrics on the app.

Cryptohome.MigrationUI.FirstScreen
Cryptohome.MigrationUI.UserChoice
Cryptohome.MigrationUI.ConsumedBatteryPercent

BUG= 714887 
TEST=Disable reboot after the migration by modifying the code, and check that chrome://histograms shows the added metrics.

Review-Url: https://codereview.chromium.org/2849833002
Cr-Commit-Position: refs/heads/master@{#468241}

[modify] https://crrev.com/b75aa7267969141e12f5ece554be20d81d39b044/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc
[modify] https://crrev.com/b75aa7267969141e12f5ece554be20d81d39b044/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.h
[modify] https://crrev.com/b75aa7267969141e12f5ece554be20d81d39b044/tools/metrics/histograms/histograms.xml

Requesting a merge to get more data from dogfooders.

Your change meets the bar and is auto-approved for M59. Please go ahead and merge the CL to branch 3071 manually. Please contact milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), gkihumba@(ChromeOS), Abdul Syed@(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/+/3db95f093b5dd7c3924a74b577a60a3b12e1f968

commit 3db95f093b5dd7c3924a74b577a60a3b12e1f968
Author: Naoki Fukino <fukino@chromium.org>
Date: Mon May 08 07:31:46 2017

cros: Add UMA metrics in encryption migration UI.

Some metrics about encryption migration are already recorded in cryptohomed.
In this CL, I'd like to add following UI-related UMA metrics on the app.

Cryptohome.MigrationUI.FirstScreen
Cryptohome.MigrationUI.UserChoice
Cryptohome.MigrationUI.ConsumedBatteryPercent

BUG= 714887 
TEST=Disable reboot after the migration by modifying the code, and check that chrome://histograms shows the added metrics.

Review-Url: https://codereview.chromium.org/2849833002
Cr-Commit-Position: refs/heads/master@{#468241}
(cherry picked from commit b75aa7267969141e12f5ece554be20d81d39b044)

Review-Url: https://codereview.chromium.org/2871493002 .
Cr-Commit-Position: refs/branch-heads/3071@{#444}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}

[modify] https://crrev.com/3db95f093b5dd7c3924a74b577a60a3b12e1f968/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc
[modify] https://crrev.com/3db95f093b5dd7c3924a74b577a60a3b12e1f968/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.h
[modify] https://crrev.com/3db95f093b5dd7c3924a74b577a60a3b12e1f968/tools/metrics/histograms/histograms.xml