Make git non-interactive when checking for src-internal access

Make git non-interactive when checking for src-internal access

git sometimes blocks asking for a password. On a random machine that
didn't know anything about google/chromium, it failed immediately with

"fatal: could not read Username for 'https://chrome-internal.googlesource.com': No such file or directory"

but on my real machine w/o _netrc it blocks and wants this:

Username for 'https://chrome-internal.googlesource.com':
Password for 'https://chrome-internal.googlesource.com':

There's no --non-interactive unfortunately, it's supposed to magically
decide if it's connected to a tty and behave appropriately. It does
not, perhaps because of being wrapped in depot_tools .bat files,
perhaps an msysgit-port bug, perhaps being called from python. Anyway
https://github.com/bower/bower/issues/1009 had a magic incantation
that works for this case: 'true' is available in the msys
distribution.

R=iannucci@chromium.org
BUG=323300
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=253844

[iannucci, 2014-02-27 08:58:39]

lgtm

[scottmg, 2014-02-27 16:57:56]

The CQ bit was checked by scottmg@chromium.org

[commit-bot: I haz the power, 2014-02-27 16:58:01]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/scottmg@chromium.org/182553004/1

[commit-bot: I haz the power, 2014-02-27 17:00:18]

Change committed as 253844

[Nico, 2014-03-05 00:58:35]

(re CL description: I believe setting usepty = 0 in buildbot.tac on that bot
would've fixed this too)

[scottmg, 2014-03-05 02:52:46]

On 2014/03/05 00:58:35, Nico wrote:
> (re CL description: I believe setting usepty = 0 in buildbot.tac on that bot
> would've fixed this too)

It wasn't on a bot, was someone on #chromium having trouble.