Checking PrefService* validity before its usage.

Checking PrefService* validity before its usage.

PrefService* returned by g_browser_process->local_state() should be checked before
its access any function in PrefService.

BUG=484163
Committed: https://crrev.com/9793a4f9ca10e3804b4f5a594655df70da10d196
Cr-Commit-Position: refs/heads/master@{#328121}

[Deepak, 2015-05-04 12:55:32]

deepak.m1@samsung.com changed reviewers:
+ mlerman@chromium.org

[Deepak, 2015-05-04 12:55:33]

PTAL at this small change.
Thanks

[Mike Lerman, 2015-05-04 13:00:57]

I have no problems with the change - but what does this accomplish / what
problem is this trying to solve? In Debug builds we haven't solved the crash
(just changed what error message gets sent out) and in Release builds there's no
change, since DCHECKs are only for Debug builds.

[Deepak, 2015-05-04 13:06:33]

On 2015/05/04 13:00:57, Mike Lerman wrote:
> I have no problems with the change - but what does this accomplish / what
> problem is this trying to solve? In Debug builds we haven't solved the crash
> (just changed what error message gets sent out) and in Release builds there's
no
> change, since DCHECKs are only for Debug builds.

I was just going through the code and find the need to check for PrefService*
before its usage.
So added this check.
With debug build it give better error checking.
Currently it is not solving any issue, but kind of defensive check.

[Mike Lerman, 2015-05-04 13:40:19]

lgtm

[Deepak, 2015-05-04 13:40:46]

On 2015/05/04 13:40:19, Mike Lerman wrote:
> lgtm

Thanks.

[Deepak, 2015-05-04 13:40:49]

The CQ bit was checked by deepak.m1@samsung.com

[commit-bot: I haz the power, 2015-05-04 13:41:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1119323002/1

[commit-bot: I haz the power, 2015-05-04 14:30:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-04 14:31:17]

Patchset 1 (id:??) landed as
https://crrev.com/9793a4f9ca10e3804b4f5a594655df70da10d196
Cr-Commit-Position: refs/heads/master@{#328121}