Moves ash content specific tests into ash_content_unittests

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 c7c69d4d02ad2e8c76882da0bf2f1b831f085a32..580b5d6bda57909f1b4bda69bd51038de353cf1b 100644
--- a/testing/buildbot/chromium.chromiumos.json
+++ b/testing/buildbot/chromium.chromiumos.json
@@ -90,6 +90,12 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "ash_content_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ash_unittests"
       },
       {
@@ -423,6 +429,12 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "ash_content_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ash_unittests"
       },
       {
@@ -783,6 +795,12 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "ash_content_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ash_unittests"
       },
       {