Add mustash tests to Ozone CrOS trybot.

testing/buildbot/chromium.chromiumos.json

Index: testing/buildbot/chromium.chromiumos.json
diff --git a/testing/buildbot/chromium.chromiumos.json b/testing/buildbot/chromium.chromiumos.json
index 585b66fd62c69d1ad7479c8692991b31faa41d3b..37b6e15eea47660c32bc760defdfce67f58fa2c9 100644
--- a/testing/buildbot/chromium.chromiumos.json
+++ b/testing/buildbot/chromium.chromiumos.json
@@ -244,6 +244,15 @@
         "test": "midi_unittests"
       },
       {
+        "args": [
+          "--override-use-gl-with-osmesa-for-tests"
+        ],
+        "swarming": {
+          "can_use_on_swarming_builders": false
+        },
+        "test": "mus_demo_unittests"
+      },
+      {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
@@ -367,6 +376,24 @@
         "test": "url_unittests"
       },
       {
+        "args": [
+          "--override-use-gl-with-osmesa-for-tests"
+        ],
+        "swarming": {
+          "can_use_on_swarming_builders": false
+        },
+        "test": "views_mus_interactive_ui_tests"
+      },
+      {
+        "args": [
+          "--override-use-gl-with-osmesa-for-tests"
+        ],
+        "swarming": {
+          "can_use_on_swarming_builders": false
+        },
+        "test": "views_mus_unittests"
+      },
+      {
         "swarming": {
           "can_use_on_swarming_builders": true
         },