Revert of Revert of Swarm cc_unittests.

testing/buildbot/chromium.mac.json

Index: testing/buildbot/chromium.mac.json
diff --git a/testing/buildbot/chromium.mac.json b/testing/buildbot/chromium.mac.json
index 8f8a30ede86ce1b3d140feca0cada2363fa4d549..1e9f0e693cfe1f04fa93ccdfdffe648835236c20 100644
--- a/testing/buildbot/chromium.mac.json
+++ b/testing/buildbot/chromium.mac.json
@@ -28,7 +28,12 @@
       },
       "cacheinvalidation_unittests",
       "cast_unittests",
-      "cc_unittests",
+      {
+        "test": "cc_unittests",
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        }
+      },
       "chromedriver_unittests",
       {
         "test": "components_unittests",
@@ -167,7 +172,12 @@
       },
       "cacheinvalidation_unittests",
       "cast_unittests",
-      "cc_unittests",
+      {
+        "test": "cc_unittests",
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        }
+      },
       "chromedriver_unittests",
       {
         "test": "components_unittests",
@@ -306,7 +316,12 @@
       },
       "cacheinvalidation_unittests",
       "cast_unittests",
-      "cc_unittests",
+      {
+        "test": "cc_unittests",
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        }
+      },
       "chromedriver_unittests",
       {
         "test": "components_unittests",
@@ -445,7 +460,12 @@
       },
       "cacheinvalidation_unittests",
       "cast_unittests",
-      "cc_unittests",
+      {
+        "test": "cc_unittests",
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        }
+      },
       "chromedriver_unittests",
       {
         "test": "components_unittests",