Make roll_dep.py work on Windows

Make roll_dep.py work on Windows

Didn't have any shell=True for git.bat/cmd.

Was able to upload https://codereview.chromium.org/1151373003 after
this CL (though the printed description didn't make it to Rietveld,
not sure if it normally does that.)

R=maruel@chromium.org

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=295397

[M-A Ruel, 2015-05-22 20:16:13]

lgtm

https://codereview.chromium.org/1151373003/diff/1/roll_dep.py
File roll_dep.py (right):

https://codereview.chromium.org/1151373003/diff/1/roll_dep.py#newcode23
roll_dep.py:23: if 'shell' not in kwargs:
kwargs.setdefault('shell', NEED_SHELL)

https://codereview.chromium.org/1151373003/diff/1/roll_dep.py#newcode30
roll_dep.py:30: if 'shell' not in kwargs:
same

[scottmg, 2015-05-23 00:41:25]

https://codereview.chromium.org/1151373003/diff/1/roll_dep.py
File roll_dep.py (right):

https://codereview.chromium.org/1151373003/diff/1/roll_dep.py#newcode23
roll_dep.py:23: if 'shell' not in kwargs:
On 2015/05/22 20:16:13, M-A Ruel wrote:
> kwargs.setdefault('shell', NEED_SHELL)

Done.

https://codereview.chromium.org/1151373003/diff/1/roll_dep.py#newcode30
roll_dep.py:30: if 'shell' not in kwargs:
On 2015/05/22 20:16:13, M-A Ruel wrote:
> same

Done.

[scottmg, 2015-05-23 00:41:36]

The CQ bit was checked by scottmg@chromium.org

[scottmg, 2015-05-23 00:41:37]

The patchset sent to the CQ was uploaded after l-g-t-m from maruel@chromium.org
Link to the patchset: https://codereview.chromium.org/1151373003/#ps20001
(title: "setdefault")

[commit-bot: I haz the power, 2015-05-23 00:41:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1151373003/20001

[commit-bot: I haz the power, 2015-05-23 00:44:49]

Committed patchset #2 (id:20001) as
http://src.chromium.org/viewvc/chrome?view=rev&revision=295397