The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/872d90082670d11e91a960c1783e1816873414a7

commit 872d90082670d11e91a960c1783e1816873414a7
Author: malaykeshav <malaykeshav@chromium.org>
Date: Thu Jun 30 20:07:49 2016

Adds a new checkbox for backup and restore in opt-in flow.

- Implements UI for opt-in flow to add checkbox for backup and
  restore.
- Adds a new preference flag to store the user preference for backup
  and restore. This will later on be sent to android via arc bridge
  service.
- Adds strings to be displayed.

BUG= 624868 
COMPONENT=CrOS Strings, Arc, Arc Opt-In UI, Preference
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2104893003
Cr-Commit-Position: refs/heads/master@{#403261}

[modify] https://crrev.com/872d90082670d11e91a960c1783e1816873414a7/chrome/app/chromeos_strings.grdp
[modify] https://crrev.com/872d90082670d11e91a960c1783e1816873414a7/chrome/browser/chromeos/arc/arc_auth_service.cc
[modify] https://crrev.com/872d90082670d11e91a960c1783e1816873414a7/chrome/browser/chromeos/arc/arc_support_host.cc
[modify] https://crrev.com/872d90082670d11e91a960c1783e1816873414a7/chrome/browser/chromeos/arc/arc_support_host.h
[modify] https://crrev.com/872d90082670d11e91a960c1783e1816873414a7/chrome/browser/resources/chromeos/arc_support/background.js
[modify] https://crrev.com/872d90082670d11e91a960c1783e1816873414a7/chrome/browser/resources/chromeos/arc_support/main.css
[modify] https://crrev.com/872d90082670d11e91a960c1783e1816873414a7/chrome/browser/resources/chromeos/arc_support/main.html
[modify] https://crrev.com/872d90082670d11e91a960c1783e1816873414a7/chrome/common/pref_names.cc
[modify] https://crrev.com/872d90082670d11e91a960c1783e1816873414a7/chrome/common/pref_names.h

Your change meets the bar and is auto-approved for M53 (branch: 2785)

Appeared that the merge was landed few hours before branching, so it's already in M53 (2785).