Reland Automatically download gold plugin for cfi builds.

Reland Automatically download gold plugin for cfi builds.

This relands https://codereview.chromium.org/1303183005

BUG=chromium:515782
LOG=n
TBR=bmeurer@chromium.org

Committed: https://crrev.com/589a095200779c564ac2a027233c515285ff5e00
Cr-Commit-Position: refs/heads/master@{#30567}

[Michael Achenbach, 2015-09-03 13:22:04]

machenbach@chromium.org changed reviewers:
+ bmeurer@chromium.org, tandrii@chromium.org

[Michael Achenbach, 2015-09-03 13:22:05]

PTAL. Original CL + ignore windows...

https://codereview.chromium.org/1330623002/diff/1/build/download_gold_plugin.py
File build/download_gold_plugin.py (right):

https://codereview.chromium.org/1330623002/diff/1/build/download_gold_plugin....
build/download_gold_plugin.py:18: # Bail out on windows and cygwin.
This bailout is new compared to the original CL.

[Michael Achenbach, 2015-09-03 13:22:10]

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

[commit-bot: I haz the power, 2015-09-03 13:22:24]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1330623002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1330623002/1

[tandrii(chromium), 2015-09-03 13:24:38]

lgtm

[Michael Achenbach, 2015-09-03 14:06:56]

The CQ bit was unchecked by machenbach@chromium.org

[Michael Achenbach, 2015-09-03 14:07:02]

The CQ bit was checked by machenbach@chromium.org

[commit-bot: I haz the power, 2015-09-03 14:07:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1330623002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1330623002/1

[commit-bot: I haz the power, 2015-09-03 14:18:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-03 14:18:34]

Patchset 1 (id:??) landed as
https://crrev.com/589a095200779c564ac2a027233c515285ff5e00
Cr-Commit-Position: refs/heads/master@{#30567}