Don't launch sub-process through shell.

Don't launch sub-process through shell.

Setting shell=True causes CygWin to open a Python
interactive prompt rather than download/copy file.
Since there are no actual shell meta-characters in
the command, there shouldn't be any problems in
forking the command directly.

BUG=

Committed: https://crrev.com/2fc996195ef56017d369313af60a8946e52e1fb9
Cr-Commit-Position: refs/heads/master@{#339086}

[bcwhite, 2015-07-16 15:34:16]

bcwhite@chromium.org changed reviewers:
+ chrisha@chromium.org, thakis@chromium.org

[bcwhite, 2015-07-16 15:35:15]

The CQ bit was checked by bcwhite@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-07-16 15:37:20]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1231863014/1

[commit-bot: I haz the power, 2015-07-16 15:46:08]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-16 15:46:09]

Dry run: This issue passed the CQ dry run.

[chrisha, 2015-07-16 17:47:41]

The CQ bit was checked by chrisha@chromium.org

[chrisha, 2015-07-16 17:47:41]

lgtm

[chrisha, 2015-07-16 17:47:52]

The CQ bit was unchecked by chrisha@chromium.org

[Nico, 2015-07-16 17:52:09]

rs-lgtm

(shell=False is the default, so you can just remove that parameter altogether if
you want)

[bcwhite, 2015-07-16 18:39:16]

On 2015/07/16 17:52:09, Nico wrote:
> rs-lgtm
> 
> (shell=False is the default, so you can just remove that parameter altogether
if
> you want)

I considered that but chose to leave it in because it fails if True and this at
least hints that it is a purposeful setting.

[bcwhite, 2015-07-16 18:39:29]

The CQ bit was checked by bcwhite@chromium.org

[commit-bot: I haz the power, 2015-07-16 18:40:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1231863014/1

[commit-bot: I haz the power, 2015-07-16 18:45:04]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-16 18:46:12]

Patchset 1 (id:??) landed as
https://crrev.com/2fc996195ef56017d369313af60a8946e52e1fb9
Cr-Commit-Position: refs/heads/master@{#339086}