Detail can be found here:
http://b/30980543

https://codereview.chromium.org/2277593002/

https://codereview.chromium.org/2277593002/ needs to be merged for ARC++

[Automated comment] Less than 2 weeks to go before stable on M53, manual review required.

Can a TPM look at this merge request please :) 

This seems specific enough to ARC++ that it should be safe for the rest of the fleet, this could warrant merging if this is a stable release blocker.

If we take comment 3 to imply this is a release blocking bug, we should probably merge it.

if we are agreed on merging this please do so asap.

Re #8 Can you take a look at https://bugs.chromium.org/p/chromium/issues/detail?id=642907? These two patches should be merged together.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a64fbac37a6616c25eed4d47fff1e8587bdd68c4

commit a64fbac37a6616c25eed4d47fff1e8587bdd68c4
Author: Luis Hector Chavez <lhchavez@google.com>
Date: Fri Sep 02 21:52:55 2016

[Merge to M53]arc: Enable user control for Arc package sync.

Current Arc package sync implemetation does not support stop sync and re-enable
sync without rebooting. So user control of arc package sync is not achievable.
This patch re-implement sync stop and enable proper user control of arc package
sync using apps checkbox in advanced sync settings.

BUG= 641011 , http://b/31034323, http://b/30640291, http://b/30980543
TEST=Pass sync integration test.
TEST=Manual test1. Turn on apps sync settings. Enable Arc and install package.
Nuke Arc then enable arc. Package restored.
TEST=Manual test2. Turn on apps sync settings. Enable Arc and install package.
Turn off apps sync settings and then nuke Arc. Then enable arc. Package not
restored. Then turn on apps sync settings. Package restored.

TBR=stevenjb@chromium.org, pavely@chromium.org
Review-Url: https://codereview.chromium.org/2277593002
Cr-Commit-Position: refs/heads/master@{#414277}
(cherry picked from commit 9b98997de0b7f4fa5054ac7c9cc5b5778a09e2c1)

Review URL: https://codereview.chromium.org/2311463002 .

Cr-Commit-Position: refs/branch-heads/2785@{#818}
Cr-Branched-From: 68623971be0cfc492a2cb0427d7f478e7b214c24-refs/heads/master@{#403382}

[modify] https://crrev.com/a64fbac37a6616c25eed4d47fff1e8587bdd68c4/chrome/browser/ui/app_list/arc/arc_app_list_prefs.cc
[modify] https://crrev.com/a64fbac37a6616c25eed4d47fff1e8587bdd68c4/chrome/browser/ui/app_list/arc/arc_package_sync_data_type_controller.cc
[modify] https://crrev.com/a64fbac37a6616c25eed4d47fff1e8587bdd68c4/chrome/browser/ui/app_list/arc/arc_package_sync_data_type_controller.h
[modify] https://crrev.com/a64fbac37a6616c25eed4d47fff1e8587bdd68c4/chrome/browser/ui/app_list/arc/arc_package_syncable_service.cc
[modify] https://crrev.com/a64fbac37a6616c25eed4d47fff1e8587bdd68c4/components/sync_driver/sync_prefs.cc
[modify] https://crrev.com/a64fbac37a6616c25eed4d47fff1e8587bdd68c4/components/sync_driver/sync_prefs_unittest.cc