Fixed merge of device settings.

Fixed merge of device settings.

BUG=430042
TEST=manual tests on a falco device

[ygorshenin1, 2014-11-07 14:15:15]

ygorshenin@chromium.org changed reviewers:
+ mnissler@chromium.org

[Mattias Nissler (ping if slow), 2014-11-07 16:07:36]

https://codereview.chromium.org/709763002/diff/1/chrome/browser/chromeos/owne...
File chrome/browser/chromeos/ownership/owner_settings_service_chromeos.cc
(right):

https://codereview.chromium.org/709763002/diff/1/chrome/browser/chromeos/owne...
chrome/browser/chromeos/ownership/owner_settings_service_chromeos.cc:215:
template <template <typename> class R, typename E>
Could use better names for R and E to indicate what they are.

https://codereview.chromium.org/709763002/diff/1/chrome/browser/chromeos/owne...
chrome/browser/chromeos/ownership/owner_settings_service_chromeos.cc:228:
*to->Add() = f;
If merging only ever adds fields, how would I actually remove an entry from a
list? If I'm not mistaken, updating for example the user whitelist by removing
an entry will actually trigger a full write of the list - the expectation is
that the data in device settings will be replaced by this new version of the
list instead of being merged. Am I missing something?

[ygorshenin1, 2014-11-07 17:24:32]

https://codereview.chromium.org/709763002/diff/1/chrome/browser/chromeos/owne...
File chrome/browser/chromeos/ownership/owner_settings_service_chromeos.cc
(right):

https://codereview.chromium.org/709763002/diff/1/chrome/browser/chromeos/owne...
chrome/browser/chromeos/ownership/owner_settings_service_chromeos.cc:228:
*to->Add() = f;
On 2014/11/07 16:07:35, Mattias Nissler wrote:
> If merging only ever adds fields, how would I actually remove an entry from a
> list? If I'm not mistaken, updating for example the user whitelist by removing
> an entry will actually trigger a full write of the list - the expectation is
> that the data in device settings will be replaced by this new version of the
> list instead of being merged. Am I missing something?

You're right, it's impossible to remove values from a list. It seems that that
solution doesn't work. I think it's better to implement a key-value storage in
OwnerSettingsService for pending changes. I'll upload a changelist for your
review soon.