gn-mode: Clear indent-tabs-mode

gn-mode: Clear indent-tabs-mode

GN does not allow tabs, so the mode should always set
indent-tabs-mode to nil (off), regardless of the user's
global setting.

R=erg@chromium.org
BUG=

Committed: https://crrev.com/dfba3a3b99597d2c7f9ce0f3c7021f03a6afc300
Cr-Commit-Position: refs/heads/master@{#348753}

[Elliot Glaysher, 2015-09-14 22:39:16]

"Bad content. Try to upload again."

(That said, if all you are doing is a setq-local to override the global setting,
then lgtm. I also wouldn't have caught this since I run with indent-tabs-mode
off by default.)

[Roland McGrath, 2015-09-14 22:41:46]

On 2015/09/14 22:39:16, Elliot Glaysher wrote:
> "Bad content. Try to upload again."
> 
> (That said, if all you are doing is a setq-local to override the global
setting,
> then lgtm. I also wouldn't have caught this since I run with indent-tabs-mode
> off by default.)

That's exactly what it is.  Three attempts and still losing.  I don't know what
that's about.
I assume I can't use the CQ if the upload failed.

[Roland McGrath, 2015-09-14 22:46:16]

The CQ bit was checked by mcgrathr@chromium.org

[Roland McGrath, 2015-09-14 22:46:16]

The patchset sent to the CQ was uploaded after l-g-t-m from erg@chromium.org
Link to the patchset: https://codereview.chromium.org/1341943002/#ps80001
(title: "rietveld sucks")

[commit-bot: I haz the power, 2015-09-14 22:49:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1341943002/80001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1341943002/80001

[commit-bot: I haz the power, 2015-09-14 23:06:13]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2015-09-14 23:06:46]

Patchset 5 (id:??) landed as
https://crrev.com/dfba3a3b99597d2c7f9ce0f3c7021f03a6afc300
Cr-Commit-Position: refs/heads/master@{#348753}

[commit-bot: I haz the power, 2015-09-23 12:38:33]

Patchset 5 (id:??) landed as
https://crrev.com/dfba3a3b99597d2c7f9ce0f3c7021f03a6afc300
Cr-Commit-Position: refs/heads/master@{#348753}