Suppress -Wunused-function for nss.

Suppress -Wunused-function for nss.

In iOS builds:

../../third_party/nss/nss/lib/freebl/sysrand.c:31:1:
  warning: unused function 'rng_systemFromNoise' [-Wunused-function]
rng_systemFromNoise(unsigned char *dest, size_t maxLen)
^

BUG=573779
R=mark@chromium.org

Committed: https://chromium.googlesource.com/chromium/deps/nss/+/225bfc39c93dfb7c7d0d1162f81e9bb5cd356c30

[Nico, 2016-01-03 23:26:38]

thakis@chromium.org changed reviewers:
+ davidben@chromium.org

[Nico, 2016-01-04 17:27:20]

thakis@chromium.org changed reviewers:
+ mark@chromium.org

[Nico, 2016-01-04 17:27:20]

Mark, want to stamp this? Looks like David might be travelling.

[Mark Mentovai, 2016-01-04 17:28:42]

LGTM

[Nico, 2016-01-04 17:38:10]

Description was changed from

==========
Suppress -Wunused-function for nss.

In iOS builds:

../../third_party/nss/nss/lib/freebl/sysrand.c:31:1:
  warning: unused function 'rng_systemFromNoise' [-Wunused-function]
rng_systemFromNoise(unsigned char *dest, size_t maxLen)
^

BUG=573779
==========

to

==========
Suppress -Wunused-function for nss.

In iOS builds:

../../third_party/nss/nss/lib/freebl/sysrand.c:31:1:
  warning: unused function 'rng_systemFromNoise' [-Wunused-function]
rng_systemFromNoise(unsigned char *dest, size_t maxLen)
^

BUG=573779
R=mark@chromium.org

Committed:
https://chromium.googlesource.com/chromium/deps/nss/+/225bfc39c93dfb7c7d0d116...
==========

[Nico, 2016-01-04 17:38:11]

Committed patchset #1 (id:1) manually as
225bfc39c93dfb7c7d0d1162f81e9bb5cd356c30 (presubmit successful).