matched the prio/milestone with b/34795856

Initial stats I'm thinking about:

Migration Started
Migration Finished
Migration Restarted
Migration Failed
Files Skipped
Bytes Migrated
Time taken to migrate

We'd like to get something on how many users are actually using ecryptfs/ext4 crypto.
And how many users are using the system with postponing migration.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bfce95b70e45ee513b3735e27660fbecc1eeea5f

commit bfce95b70e45ee513b3735e27660fbecc1eeea5f
Author: dspaid <dspaid@chromium.org>
Date: Fri Apr 21 05:21:28 2017

Add UMA stats for chromeos dircrypto migration.

There are a number of statistics we would like to track when
migrating chromeos users' home directories from ecryptfs to ext4-crypto
based encryption.

BUG= 688901 
TEST=./validate_format.py && ./pretty_print.py

Review-Url: https://codereview.chromium.org/2780103002
Cr-Commit-Position: refs/heads/master@{#466266}

[modify] https://crrev.com/bfce95b70e45ee513b3735e27660fbecc1eeea5f/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/f7c99eb365238fd6f03cb80640243e1229dad9db

commit f7c99eb365238fd6f03cb80640243e1229dad9db
Author: Dan Spaid <dspaid@google.com>
Date: Sat Apr 22 04:57:42 2017

cryptohome: Add uma stats for dircrypto migration.

Add new UMA histograms for:
 Total migration time
 Migration status
 Files skipped
 Data migrated

BUG= chromium:688901 
TEST=TEST=cros_workon_make --board=samus --test cryptohome

Change-Id: I596f80c2f6cf18ec6e011631ee075f627c8224e8
Reviewed-on: https://chromium-review.googlesource.com/456958
Commit-Ready: Dan Spaid <dspaid@chromium.org>
Tested-by: Dan Spaid <dspaid@chromium.org>
Reviewed-by: Kazuhiro Inaba <kinaba@chromium.org>
Reviewed-by: Ryo Hashimoto <hashimoto@chromium.org>

[modify] https://crrev.com/f7c99eb365238fd6f03cb80640243e1229dad9db/cryptohome/dircrypto_data_migrator/migration_helper.cc
[modify] https://crrev.com/f7c99eb365238fd6f03cb80640243e1229dad9db/cryptohome/cryptohome_metrics.cc
[modify] https://crrev.com/f7c99eb365238fd6f03cb80640243e1229dad9db/cryptohome/cryptohome_metrics.h

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

 - Seems like you need "Files Migrated" which is a big factor affecting migration time.
 - The original bug was about getting stats on how many people are actually using ecryptfs/ext4 crypto is that going to get done.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1a502b46093265ccb60c5deaf3c5707138e26be8

commit 1a502b46093265ccb60c5deaf3c5707138e26be8
Author: dspaid <dspaid@chromium.org>
Date: Mon Apr 24 01:11:15 2017

Add UMA stats for chromeos dircrypto migration.

There are a number of statistics we would like to track when
migrating chromeos users' home directories from ecryptfs to ext4-crypto
based encryption.

BUG= 688901 
TEST=./validate_format.py && ./pretty_print.py
NOTRY=true
NOPRESUBMIT=true

Review-Url: https://codereview.chromium.org/2780103002
Cr-Commit-Position: refs/heads/master@{#466266}
(cherry picked from commit bfce95b70e45ee513b3735e27660fbecc1eeea5f)

Review-Url: https://codereview.chromium.org/2835883002
Cr-Commit-Position: refs/branch-heads/3071@{#152}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}

[modify] https://crrev.com/1a502b46093265ccb60c5deaf3c5707138e26be8/tools/metrics/histograms/histograms.xml

Ok, we should have the original request in the description (how many users have started/finished migration) done.  I missed the "how many users are using ext4" since it was just in the title, will add a new histogram for that.
I'll also create a new bug for the UI-related stats that we may want to track.

Filed 714926 for the "how many users are using ext4 encryption" stat since the patches in this issue have already been merged to M-59.  Closing this as resolved.

I see https://bugs.chromium.org/p/chromium/issues/detail?id=714926 for UI stats.

https://bugs.chromium.org/p/chromium/issues/detail?id=714926 is for how many users are using ext4-crypto versus ecryptfs.  https://bugs.chromium.org/p/chromium/issues/detail?id=714887 is for UI stats (how many users skipped, how many users started from the android app icon)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/44497d6d2dcb0b4b76d68e9211847831b5077b39

commit 44497d6d2dcb0b4b76d68e9211847831b5077b39
Author: Dan Spaid <dspaid@google.com>
Date: Wed Apr 26 05:52:44 2017

cryptohome: Add uma stats for dircrypto migration.

Add new UMA histograms for:
 Total migration time
 Migration status
 Files skipped
 Data migrated

BUG= chromium:688901 
TEST=TEST=cros_workon_make --board=samus --test cryptohome

Change-Id: I596f80c2f6cf18ec6e011631ee075f627c8224e8
Reviewed-on: https://chromium-review.googlesource.com/456958
Commit-Ready: Dan Spaid <dspaid@chromium.org>
Tested-by: Dan Spaid <dspaid@chromium.org>
Reviewed-by: Kazuhiro Inaba <kinaba@chromium.org>
Reviewed-by: Ryo Hashimoto <hashimoto@chromium.org>
(cherry picked from commit f7c99eb365238fd6f03cb80640243e1229dad9db)
Reviewed-on: https://chromium-review.googlesource.com/487764
Reviewed-by: Dan Spaid <dspaid@chromium.org>
Commit-Queue: Dan Spaid <dspaid@chromium.org>

[modify] https://crrev.com/44497d6d2dcb0b4b76d68e9211847831b5077b39/cryptohome/dircrypto_data_migrator/migration_helper.cc
[modify] https://crrev.com/44497d6d2dcb0b4b76d68e9211847831b5077b39/cryptohome/cryptohome_metrics.cc
[modify] https://crrev.com/44497d6d2dcb0b4b76d68e9211847831b5077b39/cryptohome/cryptohome_metrics.h