arc: Fix issue when Arc OptIn is not started on fresh devices.

arc: Fix issue when Arc OptIn is not started on fresh devices.

BUG=599668
TEST=Manually tested on devices. Arc OptIn started on fresh devices.

Committed: https://crrev.com/fc1fa4a9665f8720776d9e790751d8feddb72752
Cr-Commit-Position: refs/heads/master@{#384431}

[khmel, 2016-03-31 22:19:20]

khmel@chromium.org changed reviewers:
+ xiyuan@chromium.org

[khmel, 2016-03-31 22:19:21]

https://codereview.chromium.org/1854463002/diff/1/chrome/browser/chromeos/arc...
File chrome/browser/chromeos/arc/arc_auth_service.cc (right):

https://codereview.chromium.org/1854463002/diff/1/chrome/browser/chromeos/arc...
chrome/browser/chromeos/arc/arc_auth_service.cc:231:
PrefServiceSyncableFromProfile(profile_)->AddObserver(this);
In one of the recent CLs I changed observer scheme 

from:
PrefChangeRegistrar pref_change_registrar_;
pref_change_registrar_.Add(prefs::kArcEnabled, ...)

To:
PrefServiceSyncableFromProfile(profile_)->
AddSyncedPrefObserver(prefs::kArcEnabled, this);

This was done to handle UMA statics properly in order to filter local vs synced
changes.

However SyncedPrefObserver is not triggered when initial sync occurred (for new
profile).
Workaround is to double check ArcEnabled pref on syncing is ready.

I also tested following case:
Enabled Arc on device, Logout, Disable Arc on another device,
Restart device and change was tracked. In this case, it was synced.

WDYT?

[xiyuan, 2016-03-31 22:32:44]

lgtm

https://codereview.chromium.org/1854463002/diff/1/chrome/browser/chromeos/arc...
File chrome/browser/chromeos/arc/arc_auth_service.cc (right):

https://codereview.chromium.org/1854463002/diff/1/chrome/browser/chromeos/arc...
chrome/browser/chromeos/arc/arc_auth_service.cc:251: if (!disable_ui_for_testing
&& profile_->IsNewProfile() &&
nit: profile_->IsNewProfile() might not be necessary.

[khmel, 2016-03-31 22:47:34]

https://codereview.chromium.org/1854463002/diff/1/chrome/browser/chromeos/arc...
File chrome/browser/chromeos/arc/arc_auth_service.cc (right):

https://codereview.chromium.org/1854463002/diff/1/chrome/browser/chromeos/arc...
chrome/browser/chromeos/arc/arc_auth_service.cc:251: if (!disable_ui_for_testing
&& profile_->IsNewProfile() &&
On 2016/03/31 22:32:44, xiyuan wrote:
> nit: profile_->IsNewProfile() might not be necessary.

I think it might be required.
For example:
User starts first time and we show Notification. User ignores this and
notification is timed out. User starts next time, in this case profile is not
new, but it still has no kArcEnabled path. In this case we would show
notification second time and this is not expected from UI design.

[xiyuan, 2016-03-31 22:50:50]

https://codereview.chromium.org/1854463002/diff/1/chrome/browser/chromeos/arc...
File chrome/browser/chromeos/arc/arc_auth_service.cc (right):

https://codereview.chromium.org/1854463002/diff/1/chrome/browser/chromeos/arc...
chrome/browser/chromeos/arc/arc_auth_service.cc:251: if (!disable_ui_for_testing
&& profile_->IsNewProfile() &&
On 2016/03/31 22:47:34, khmel wrote:
> On 2016/03/31 22:32:44, xiyuan wrote:
> > nit: profile_->IsNewProfile() might not be necessary.
> 
> I think it might be required.
> For example:
> User starts first time and we show Notification. User ignores this and
> notification is timed out. User starts next time, in this case profile is not
> new, but it still has no kArcEnabled path. In this case we would show
> notification second time and this is not expected from UI design.

Okay. That sounds like a valid case.

[khmel, 2016-03-31 22:51:28]

The CQ bit was checked by khmel@chromium.org

[commit-bot: I haz the power, 2016-03-31 22:52:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1854463002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1854463002/1

[commit-bot: I haz the power, 2016-03-31 23:33:17]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-31 23:34:16]

Description was changed from

==========
arc: Fix issue when Arc OptIn is not started on fresh devices.

BUG=599668
TEST=Manually tested on devices. Arc OptIn started on fresh devices.
==========

to

==========
arc: Fix issue when Arc OptIn is not started on fresh devices.

BUG=599668
TEST=Manually tested on devices. Arc OptIn started on fresh devices.

Committed: https://crrev.com/fc1fa4a9665f8720776d9e790751d8feddb72752
Cr-Commit-Position: refs/heads/master@{#384431}
==========

[commit-bot: I haz the power, 2016-03-31 23:34:17]

Patchset 1 (id:??) landed as
https://crrev.com/fc1fa4a9665f8720776d9e790751d8feddb72752
Cr-Commit-Position: refs/heads/master@{#384431}