CrOS: Load Chromite pins from JSON.

CrOS: Load Chromite pins from JSON.

Rework `cros_chromite` script to load its Chromite pins from a JSON file
instead of having be embedded in the script itself. This will allow external
tools to easily update Chromite pins.

BUG=chromium:543290
TEST=local

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=297261

[dnj, 2015-10-15 18:46:46]

dnj@chromium.org changed reviewers:
+ stip@chromium.org

[dnj, 2015-10-15 18:46:47]

PTAL

This has an internal component patch:
https://chromereviews.googleplex.com/272847013

This is the first step in the chain, followed by:
- https://codereview.chromium.org/1393893004
- https://codereview.chromium.org/1403313002

[dnj (Google), 2015-10-16 21:06:53]

dnj@google.com changed reviewers:
+ dnj@google.com

[dnj (Google), 2015-10-16 21:06:53]

(ping!)

[ghost stip (do not use), 2015-10-21 16:17:23]

lgtm

https://chromiumcodereview.appspot.com/1402253002/diff/1/scripts/common/env.py
File scripts/common/env.py (right):

https://chromiumcodereview.appspot.com/1402253002/diff/1/scripts/common/env.p...
scripts/common/env.py:318: sys_paths = [p for p in sys.path
I wonder if this will break things. keep an eye when this lands

[luqui1, 2015-10-22 22:19:29]

luqui@google.com changed reviewers:
+ luqui@google.com

[luqui1, 2015-10-22 22:19:29]

lgtm

[dnj (Google), 2015-10-22 23:11:45]

The CQ bit was checked by dnj@google.com

[commit-bot: I haz the power, 2015-10-22 23:11:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402253002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402253002/1

[commit-bot: I haz the power, 2015-10-22 23:13:38]

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

[commit-bot: I haz the power, 2015-10-22 23:13:39]

Try jobs failed on following builders:
  build_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/build_presubmit...)

[dnj (Google), 2015-10-22 23:18:09]

The CQ bit was checked by dnj@google.com to run a CQ dry run

[commit-bot: I haz the power, 2015-10-22 23:18:20]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402253002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402253002/20001

[commit-bot: I haz the power, 2015-10-22 23:22:18]

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

[commit-bot: I haz the power, 2015-10-22 23:22:19]

Dry run: Try jobs failed on following builders:
  build_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/build_presubmit...)

[dnj (Google), 2015-10-22 23:29:54]

The CQ bit was checked by dnj@google.com to run a CQ dry run

[commit-bot: I haz the power, 2015-10-22 23:30:00]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402253002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402253002/40001

[commit-bot: I haz the power, 2015-10-22 23:33:05]

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

[commit-bot: I haz the power, 2015-10-22 23:33:08]

Dry run: This issue passed the CQ dry run.

[dnj (Google), 2015-10-22 23:40:47]

The CQ bit was checked by dnj@google.com

[dnj (Google), 2015-10-22 23:40:47]

The patchset sent to the CQ was uploaded after l-g-t-m from luqui@google.com,
stip@chromium.org
Link to the patchset: https://codereview.chromium.org/1402253002/#ps40001
(title: "Rebase (without pin JSON).")

[commit-bot: I haz the power, 2015-10-22 23:40:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402253002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402253002/40001

[commit-bot: I haz the power, 2015-10-22 23:44:17]

Committed patchset #3 (id:40001) as
http://src.chromium.org/viewvc/chrome?view=rev&revision=297261