Fix compilation of //third_party/nss with gn on iOS.

Fix compilation of //third_party/nss with gn on iOS.

Move the cflags override into a separate config so that they are
applied after those from //build/config/compiler:no_chromium_code.

Without this change, the -Wno-unused-function is found before the
-Wall that set the -Wunused-function flag. By using a separate
config, the flags are set in order, and the -Wno-unused-function
is found after the -Wall.

BUG=459705
Committed: https://crrev.com/f5d1a9c599c7cd6833455eacb4ec694a47c1f1b0
Cr-Commit-Position: refs/heads/master@{#372546}

[sdefresne, 2016-01-29 10:29:55]

sdefresne@chromium.org changed reviewers:
+ dpranke@chromium.org

[sdefresne, 2016-01-29 10:29:56]

Please take a look.

Fixes the following compilation failures:

../../third_party/nss/nss/lib/freebl/shvfy.c:226:1: error: unused function
'mkCheckFileName' [-Werror,-Wunused-function]
mkCheckFileName(const char *libName)
^
../../third_party/nss/nss/lib/freebl/shvfy.c:249:1: error: unused function
'readItem' [-Werror,-Wunused-function]
readItem(PRFileDesc *fd, SECItem *item)
^
2 errors generated.

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

[Dirk Pranke, 2016-01-29 18:58:55]

lgtm

[sdefresne, 2016-01-30 10:14:42]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2016-01-30 10:14:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1644333002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1644333002/1

[commit-bot: I haz the power, 2016-01-30 10:18:52]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-01-30 10:19:51]

Description was changed from

==========
Fix compilation of //third_party/nss with gn on iOS.

Move the cflags override into a separate config so that they are
applied after those from //build/config/compiler:no_chromium_code.

Without this change, the -Wno-unused-function is found before the
-Wall that set the -Wunused-function flag. By using a separate
config, the flags are set in order, and the -Wno-unused-function
is found after the -Wall.

BUG=459705
==========

to

==========
Fix compilation of //third_party/nss with gn on iOS.

Move the cflags override into a separate config so that they are
applied after those from //build/config/compiler:no_chromium_code.

Without this change, the -Wno-unused-function is found before the
-Wall that set the -Wunused-function flag. By using a separate
config, the flags are set in order, and the -Wno-unused-function
is found after the -Wall.

BUG=459705

Committed: https://crrev.com/f5d1a9c599c7cd6833455eacb4ec694a47c1f1b0
Cr-Commit-Position: refs/heads/master@{#372546}
==========

[commit-bot: I haz the power, 2016-01-30 10:19:52]

Patchset 1 (id:??) landed as
https://crrev.com/f5d1a9c599c7cd6833455eacb4ec694a47c1f1b0
Cr-Commit-Position: refs/heads/master@{#372546}