Swarm net_unittests on release ChromeOS.

testing/buildbot/chromium.chromiumos.json

 {
   "Linux ChromiumOS Tests (1)": {
     "gtest_tests": [
       "accessibility_unittests",
       {
         "test": "base_unittests",
         "swarming": {
           "can_use_on_swarming_builders": true
         }
       },
@@ skipping 30 matching lines @@
       {
         "test": "interactive_ui_tests",
         "swarming": {
           "can_use_on_swarming_builders": true
         }
       },
       "jingle_unittests",
       "content_unittests",
       "device_unittests",
       "media_unittests",
-      "net_unittests",
+      {
+        "test": "net_unittests",
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        }
+      },
       "ppapi_unittests",
       "printing_unittests",
       "remoting_unittests",
       "sandbox_linux_unittests",
       "ui_unittests",
       "views_unittests",
       "wm_unittests",
       "aura_unittests",
       "ash_unittests",
       "app_list_unittests",
@@ skipping 192 matching lines @@
   },
   "Linux ChromiumOS Tests (dbg)(2)": {
     "gtest_tests": [
     ]
   },
   "Linux ChromiumOS Tests (dbg)(3)": {
     "gtest_tests": [
     ]
   }
 }