Move arch+plat logic to common.

Move arch+plat logic to common.

R=vadimsh@chromium.org
BUG=663843
Review-Url: https://codereview.chromium.org/2653843003
Committed: https://github.com/luci/luci-go/commit/bb6d936a5d171c9ab1c1d3240c7c65eda935bebb

[Vadim Sh., 2017-01-24 01:06:00]

lgtm

[iannucci, 2017-01-24 01:24:37]

The CQ bit was checked by iannucci@chromium.org

[iannucci, 2017-01-24 01:24:37]

The patchset sent to the CQ was uploaded after l-g-t-m from vadimsh@chromium.org
Link to the patchset: https://codereview.chromium.org/2653843003/#ps20001
(title: "rebase")

[commit-bot: I haz the power, 2017-01-24 01:24:39]

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, 2017-01-24 01:31:37]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1485221077132220,
"parent_rev": "8bf73ae30be5ceafe291a87fcd22ab6cb4af52ba", "commit_rev":
"bb6d936a5d171c9ab1c1d3240c7c65eda935bebb"}

[commit-bot: I haz the power, 2017-01-24 01:31:40]

Description was changed from

==========
Move arch+plat logic to common.

R=vadimsh@chromium.org
BUG=663843
==========

to

==========
Move arch+plat logic to common.

R=vadimsh@chromium.org
BUG=663843

Review-Url: https://codereview.chromium.org/2653843003
Committed:
https://github.com/luci/luci-go/commit/bb6d936a5d171c9ab1c1d3240c7c65eda935bebb
==========

[commit-bot: I haz the power, 2017-01-24 01:31:41]

Committed patchset #2 (id:20001) as
https://github.com/luci/luci-go/commit/bb6d936a5d171c9ab1c1d3240c7c65eda935bebb