Adds ash_mus_unittests to FYI bot

testing/buildbot/chromium.fyi.json

Index: testing/buildbot/chromium.fyi.json
diff --git a/testing/buildbot/chromium.fyi.json b/testing/buildbot/chromium.fyi.json
index ab62c370385fcddca15850e0a812a79c7c11f4e7..6de71f0cdf2354926a26f3292a46517f598a7331 100644
--- a/testing/buildbot/chromium.fyi.json
+++ b/testing/buildbot/chromium.fyi.json
@@ -11790,6 +11790,16 @@
     "gtest_tests": [
       {
         "args": [
+          "--mus",
+          "--test-launcher-filter-file=../../testing/buildbot/filters/ash_mus_unittests.filter"

[msw, 2017/04/06 18:43:22]

optional nit: prepend mojo.fyi to the file name like
mojo.fyi.browser_tests.filter? (or maybe that would just make it awkward to use
for non-fyi later on?)

[sky, 2017/04/06 19:00:11]

Indeed. I'm hoping this quickly transitions to the main waterfall.

+        ],
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "ash_mus_unittests"
+      },
+      {
+        "args": [
           "--override-use-software-gl-for-tests",
           "--test-launcher-filter-file=../../testing/buildbot/filters/mojo.fyi.browser_tests.filter"
         ],