Revert of [Sync] Merge sync_unit_tests into components_unit_tests.

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 ac106b3586fd27e222189a5695f1dc5191fe3fcd..6cd6fd433871e1d9a77a6b856517d37ff2c7edbf 100644
--- a/testing/buildbot/chromium.chromiumos.json
+++ b/testing/buildbot/chromium.chromiumos.json
@@ -314,6 +314,12 @@
         "test": "sql_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "sync_unit_tests"
+      },
+      {
         "test": "ui_arc_unittests"
       },
       {
@@ -650,6 +656,12 @@
         "test": "sql_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "sync_unit_tests"
+      },
+      {
         "test": "ui_arc_unittests"
       },
       {
@@ -960,6 +972,12 @@
         "test": "sql_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "sync_unit_tests"
+      },
+      {
         "test": "ui_arc_unittests"
       },
       {