remove -Wno-header-guard workaround for old versions of NSS

remove -Wno-header-guard workaround for old versions of NSS

I think it's safe to re-enable this warning now.  The bug was
fixed upstream in 3.15.1 and there have been several NSS upgrades since then.

BUG=255201
Committed: https://crrev.com/86ebf48be903b226d068b08efa16fe3725babb8c
Cr-Commit-Position: refs/heads/master@{#321711}

[Mostyn Bramley-Moore, 2015-03-21 22:55:46]

mostynb@opera.com changed reviewers:
+ thakis@chromium.org

[Mostyn Bramley-Moore, 2015-03-21 22:55:47]

@Nico: PTAL.

[Nico, 2015-03-21 23:57:48]

On 2015/03/21 22:55:47, Mostyn Bramley-Moore wrote:
> @Nico: PTAL.

Iirc think we pick up the system header, and the header on precise is this still
broken (?)

[Mostyn Bramley-Moore, 2015-03-22 01:14:45]

On 2015/03/21 23:57:48, Nico wrote:
> On 2015/03/21 22:55:47, Mostyn Bramley-Moore wrote:
> > @Nico: PTAL.
> 
> Iirc think we pick up the system header, and the header on precise is this
still
> broken (?)

/usr/include/nss/secmod.h on my only remaining precise machine looks OK, they
seem to have updated to NSS 3.17.4:

http://packages.ubuntu.com/precise/libnss3-dev

[Nico, 2015-03-22 04:22:59]

On 2015/03/22 01:14:45, Mostyn Bramley-Moore wrote:
> On 2015/03/21 23:57:48, Nico wrote:
> > On 2015/03/21 22:55:47, Mostyn Bramley-Moore wrote:
> > > @Nico: PTAL.
> > 
> > Iirc think we pick up the system header, and the header on precise is this
> still
> > broken (?)
> 
> /usr/include/nss/secmod.h on my only remaining precise machine looks OK, they
> seem to have updated to NSS 3.17.4:
> 
> http://packages.ubuntu.com/precise/libnss3-dev

OK, thanks for checking. Lgtm, we'll see if it breaks anything :-)

[Nico, 2015-03-22 04:23:05]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2015-03-22 04:23:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1028863002/1

[commit-bot: I haz the power, 2015-03-22 08:10:32]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-22 08:11:23]

Patchset 1 (id:??) landed as
https://crrev.com/86ebf48be903b226d068b08efa16fe3725babb8c
Cr-Commit-Position: refs/heads/master@{#321711}

[Mostyn Bramley-Moore, 2015-03-22 09:23:30]

mostynb@opera.com changed reviewers:
+ rsleevi@chromium.org

[Mostyn Bramley-Moore, 2015-03-22 09:25:11]

Ryan (CC'ed) mentioned that NSS 3.14.3 support is still required for some
product (but I'm not sure which)- so we may need to revert this.

[sof, 2015-03-22 10:59:57]

On 2015/03/22 09:25:11, Mostyn Bramley-Moore wrote:
> Ryan (CC'ed) mentioned that NSS 3.14.3 support is still required for some
> product (but I'm not sure which)- so we may need to revert this.

cf
http://build.chromium.org/p/chromium.webkit/builders/GPU%20Linux%20Builder%20...
?