Swarm setup_unittests on FYI bots.

testing/buildbot/chromium.win.json

Index: testing/buildbot/chromium.win.json
diff --git a/testing/buildbot/chromium.win.json b/testing/buildbot/chromium.win.json
index 4bbee12577efeae40fea81887d7523155533b1ed..b0969678d27252b09ff348e958d830175ef97b49 100644
--- a/testing/buildbot/chromium.win.json
+++ b/testing/buildbot/chromium.win.json
@@ -238,6 +238,9 @@
         "test": "sbox_validation_tests"
       },
       {
+        "test": "setup_unittests"

[M-A Ruel, 2015/07/13 20:26:00]

Please have it run on swarming, otherwise you'll become a blocker for
http://crbug.com/496321.

[grt (UTC plus 2), 2015/07/13 20:54:17]

This can't be as simple as "can_use_on_swarming_builders": true, can it? What do
I need to do to see if it actually works on swarming? .isolate-or-something? i
can haz pointer to instructions?

[M-A Ruel, 2015/07/13 22:29:57]

https://codereview.chromium.org/1220833004 is a good example.

+      },
+      {
         "swarming": {
           "can_use_on_swarming_builders": true
         },