roll_dep.py: switch to argparse

roll_dep.py: switch to argparse

This makes for cleaner code and better --help.

Also, handle case when deps directory does not exist.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=295475

[Sam Clegg, 2015-05-29 22:14:53]

sbc@chromium.org changed reviewers:
+ maruel@chromium.org

[M-A Ruel, 2015-05-29 22:57:37]

lgtm either way

https://codereview.chromium.org/1160833005/diff/1/roll_dep.py
File roll_dep.py (right):

https://codereview.chromium.org/1160833005/diff/1/roll_dep.py#newcode140
roll_dep.py:140: if args.reviewer is not None:
Actually default is ''.

I'd actually prefer to remove default='' but I prefer to keep
if args.reviewer:

[Sam Clegg, 2015-06-01 17:52:09]

On 2015/05/29 22:57:37, M-A Ruel wrote:
> lgtm either way
> 
> https://codereview.chromium.org/1160833005/diff/1/roll_dep.py
> File roll_dep.py (right):
> 
> https://codereview.chromium.org/1160833005/diff/1/roll_dep.py#newcode140
> roll_dep.py:140: if args.reviewer is not None:
> Actually default is ''.

Done.

> 
> I'd actually prefer to remove default='' but I prefer to keep
> if args.reviewer:

Done.

[Sam Clegg, 2015-06-01 18:03:34]

The CQ bit was checked by sbc@chromium.org

[Sam Clegg, 2015-06-01 18:03:35]

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/1160833005/#ps20001
(title: " ")

[commit-bot: I haz the power, 2015-06-01 18:04:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1160833005/20001

[commit-bot: I haz the power, 2015-06-01 18:07:04]

Committed patchset #2 (id:20001) as
http://src.chromium.org/viewvc/chrome?view=rev&revision=295475