Enable service_unittests on several bot configurations

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 c2f04d0d86f1b308e49832aa9ea522cd3a59ec0c..974c1fb5c9344fc269d2e06aa690a72f5c2bc699 100644
--- a/testing/buildbot/chromium.chromiumos.json
+++ b/testing/buildbot/chromium.chromiumos.json
@@ -405,6 +405,15 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "service_unittests"
+      },
+      {
+        "args": [
+          "--ozone-platform=x11"
+        ],
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "skia_unittests"
       },
       {
@@ -791,6 +800,12 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "service_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "skia_unittests"
       },
       {
@@ -1131,6 +1146,12 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "service_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "skia_unittests"
       },
       {