Update policy description for SystemUse24HourClock policy.

Update policy description for SystemUse24HourClock policy.

This clarifies the policy description to agree with the implementation
and describe the default behavior.

BUG=
TEST=None, doc update only.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=218753

[Mattias Nissler (ping if slow), 2013-08-19 12:55:29]

alemate@: Can you please review the new description for accuracy?

nkostylev@, bartfab@: OWNERS approval.

[bartfab (slow), 2013-08-19 13:03:01]

lgtm

[Nikita (slow), 2013-08-19 15:17:32]

lgtm

https://codereview.chromium.org/23125005/diff/1/chrome/app/policy/policy_temp...
File chrome/app/policy/policy_templates.json (right):

https://codereview.chromium.org/23125005/diff/1/chrome/app/policy/policy_temp...
chrome/app/policy/policy_templates.json:4083: If this pocliy is not set, the
device will default to a 12 hour clock format.''',
nit: policy

[Mattias Nissler (ping if slow), 2013-08-20 10:01:38]

alemate@: Ping, can you confirm the updated documentation is accurate?

[Alexander Alekseev, 2013-08-21 03:54:22]

> alemate@: Ping, can you confirm the updated documentation is accurate?

Sorry, I looked at the comments (both old and new) several times.
I saw that both of them are wrong, but I actually had to find my original branch
to figure out what it had been to mean.
Sorry for the delay again.

The comment:
-----------------------------
    // On login screen and in guest mode owner default is used for
    // use24HourClock preference.
    // All other modes default to the default locale value.
-----------------------------
actually reveals the original idea. But the last line was never implemented. So
it's OK to drop it.

Policy description looks good to me, except that it's wrong in default value ;-)

There is also "undocumented" corner of that policy: it should be actually called
"device owner' value of Use24HourClock user preference".
Therefore it's updated automatically when device owner changes his clock type.
And for the managed devices, that do not have device owner, it can be set via
policy.

So my verdict is: looks good to me if you set default to 24 hours format. Also
you probably know better than me, if we should add a note about connection
between this policy, device owner actions and managed devices to public
descriptions. If you think it should be added, please do it.

https://codereview.chromium.org/23125005/diff/13001/chrome/app/policy/policy_...
File chrome/app/policy/policy_templates.json (right):

https://codereview.chromium.org/23125005/diff/13001/chrome/app/policy/policy_...
chrome/app/policy/policy_templates.json:4083: If this policy is not set, the
device will default to a 12 hour clock format.''',
See:

chrome/browser/chromeos/system/ash_system_tray_delegate.cc:913: bool
ShouldUse24HourClock() const

It actually defaults to 24-hour format.

[Mattias Nissler (ping if slow), 2013-08-21 08:10:08]

Updated once more. If I don't hear disagreement, I'll commit this later today.

https://codereview.chromium.org/23125005/diff/13001/chrome/app/policy/policy_...
File chrome/app/policy/policy_templates.json (right):

https://codereview.chromium.org/23125005/diff/13001/chrome/app/policy/policy_...
chrome/app/policy/policy_templates.json:4083: If this policy is not set, the
device will default to a 12 hour clock format.''',
On 2013/08/21 03:54:22, alemate wrote:
> See:
> 
> chrome/browser/chromeos/system/ash_system_tray_delegate.cc:913: bool
> ShouldUse24HourClock() const
> 
> It actually defaults to 24-hour format.

Whoops, thanks for pointing out! Fixed.

[commit-bot: I haz the power, 2013-08-21 13:50:08]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mnissler@chromium.org/23125005/21001

[commit-bot: I haz the power, 2013-08-21 16:43:25]

Change committed as 218753