Add utility script for GPU Pixel Wranglers.

Add utility script for GPU Pixel Wranglers.

This script attempts to automate a lot of the waterfall-staring
that pixel wranglers need to do. A version is already published
and documented at
http://www.chromium.org/developers/how-tos/gpu-wrangling/check_gpu_bots-script.
This script is intended to be a temporary measure to help out
pixel wranglers until such functionality (or better) is
incorporated into tools like the sheriff-o-matic.

BUG=

Committed: https://crrev.com/75520c990bd82917fce99658ab8383f03e3525ed
Cr-Commit-Position: refs/heads/master@{#296032}

[hartmanng, 2014-09-20 17:20:55]

hartmanng@chromium.org changed reviewers:
+ piman@chromium.org

[hartmanng, 2014-09-20 17:20:55]

piman, please take a look (and let me know if this is an inappropriate place to
publish this script). Sorry for the large review.

[piman, 2014-09-22 19:12:10]

lgtm

[hartmanng, 2014-09-22 19:14:39]

Thanks!

[hartmanng, 2014-09-22 19:14:44]

The CQ bit was checked by hartmanng@chromium.org

[commit-bot: I haz the power, 2014-09-22 19:15:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/588603003/1

[commit-bot: I haz the power, 2014-09-22 20:21:15]

Committed patchset #1 (id:1) as 90822ad7511bf63f0a27f831d6e3e81297f5b853

[commit-bot: I haz the power, 2014-09-22 20:21:57]

Patchset 1 (id:??) landed as
https://crrev.com/75520c990bd82917fce99658ab8383f03e3525ed
Cr-Commit-Position: refs/heads/master@{#296032}