mac: Build third-party code with -Werror too.

mac: Build third-party code with -Werror too.

If third-party code does trigger warnings, they should be disabled
in that third-party module's gyp file instead, or if they are serious,
fixed.

BUG=none
TEST=none

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=135860

[Avi (use Gerrit), 2012-05-08 00:10:37]

+1

[Mark Mentovai, 2012-05-08 15:31:38]

I guess the bot coverage is good enough now that other-platform people will
still have plenty of advance warning of, um, warnings before things land in the
tree for real.

[Mark Mentovai, 2012-05-08 15:31:54]

LGTM

[commit-bot: I haz the power, 2012-05-08 15:36:07]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/thakis@chromium.org/10384051/1

[commit-bot: I haz the power, 2012-05-08 17:26:47]

Try job failure for 10384051-1 (retry) on win_rel for step "update".
It's a second try, previously, step "browser_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

Step "update" is always a major failure.
Look at the try server FAQ for more details.