GN: expunge all environment variables that have no effect on GN

GN: expunge all environment variables that have no effect on GN

This should have no practical effect.  I just want to make sure no
environment variables beyond $PATH have any effect on GN builds.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300173002

Committed: https://skia.googlesource.com/skia/+/ae509db48198840a607f943cf29b48765fb339da

[mtklein_C, 2016-09-01 19:38:24]

Description was changed from

==========
GN: expunge all environment variables that have no effect on GN

This should have no practical effect.  I just want to make sure no
environment variables beyond $PATH have any effect on GN builds.

BUG=skia:
==========

to

==========
GN: expunge all environment variables that have no effect on GN

This should have no practical effect.  I just want to make sure no
environment variables beyond $PATH have any effect on GN builds.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300173002
==========

[mtklein_C, 2016-09-01 19:39:40]

The CQ bit was checked by mtklein@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-01 19:39:49]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[mtklein_C, 2016-09-01 19:59:53]

mtklein@chromium.org changed reviewers:
+ borenet@google.com

[borenet, 2016-09-01 20:10:44]

LGTM

[commit-bot: I haz the power, 2016-09-01 20:17:04]

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

[commit-bot: I haz the power, 2016-09-01 20:17:05]

Dry run: This issue passed the CQ dry run.

[mtklein_C, 2016-09-01 20:17:59]

The CQ bit was checked by mtklein@chromium.org

[commit-bot: I haz the power, 2016-09-01 20:18:05]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-01 20:19:23]

Description was changed from

==========
GN: expunge all environment variables that have no effect on GN

This should have no practical effect.  I just want to make sure no
environment variables beyond $PATH have any effect on GN builds.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300173002
==========

to

==========
GN: expunge all environment variables that have no effect on GN

This should have no practical effect.  I just want to make sure no
environment variables beyond $PATH have any effect on GN builds.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300173002

Committed:
https://skia.googlesource.com/skia/+/ae509db48198840a607f943cf29b48765fb339da
==========

[commit-bot: I haz the power, 2016-09-01 20:19:24]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/ae509db48198840a607f943cf29b48765fb339da