Use chromium's gyp if third_party is not available.

Use chromium's gyp if third_party is not available.

This is for building Android.mk inside an Android tree where there
is no third_party directory.

Committed: http://code.google.com/p/skia/source/detail?r=13614

[scroggo, 2014-02-26 22:44:09]

As with https://codereview.chromium.org/178223015/, alternatively, I could have
the bot run the script before removing third_party.

Let me know if you think I should make this change, and I'll get a Python coder
to review.

[djsollen, 2014-02-27 13:53:03]

I'm completely fine with a change like this since it is used in a tool and if it
does ever break (e.g. chrome stops using gyp) we can spend time on an alternate
solution.

[scroggo, 2014-02-27 15:10:37]

On 2014/02/26 22:44:09, scroggo wrote:
> As with https://codereview.chromium.org/178223015/, alternatively, I could
have
> the bot run the script before removing third_party.

As with https://codereview.chromium.org/178223015/, I was mistaken; gyp is in
third_party/external, which we won't have before removing third_party, unless we
do a gclient sync. So I think this change is the right approach.

[epoger, 2014-02-27 18:33:44]

Python code LGTM

I'll defer to your guys' call as to whether the change is advisable at a high
level. :-)

[scroggo, 2014-02-27 18:40:32]

The CQ bit was checked by scroggo@google.com

[commit-bot: I haz the power, 2014-02-27 18:40:38]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/scroggo@google.com/177073022/20001

[commit-bot: I haz the power, 2014-02-27 18:58:53]

Change committed as 13614