Ignore ManagedState changes to existing state.

Ignore ManagedState changes to existing state.

Changing state to an existing state is a no-op that produces event log 
noise and extra callbacks.

BUG=239652
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=200229

[stevenjb, 2013-05-13 16:38:21]

Please review as soon as convenient.

[pneubeck (no reviews), 2013-05-14 16:31:51]

On 2013/05/13 16:38:21, stevenjb (chromium) wrote:
> Please review as soon as convenient.

the changes to the header got lost.
Please take care of:
  dns_servers_.clear();  in  NetworkState::PropertyChanged
which also modifies the state.

[stevenjb, 2013-05-14 17:18:25]

On 2013/05/14 16:31:51, pneubeck wrote:
> On 2013/05/13 16:38:21, stevenjb (chromium) wrote:
> > Please review as soon as convenient.
> 
> the changes to the header got lost.
Added.

> Please take care of:
>   dns_servers_.clear();  in  NetworkState::PropertyChanged
> which also modifies the state.
I intentionally did not want to add a complex comparison for a property that I
don't expect to change frequently anyway. Updated the comment appropriately.

PTAL

[pneubeck (no reviews), 2013-05-14 20:34:56]

lgtm

[commit-bot: I haz the power, 2013-05-14 20:58:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/[email protected]/15132004/8003

[commit-bot: I haz the power, 2013-05-15 10:01:28]

Change committed as 200229