Convert jingle_unittests to run exclusively on Swarming

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 480aa32e22be18c5254b69e77b4f5f9c7ab2979c..abb6792b17374b41656958cf6a087ff1001ad5aa 100644
--- a/testing/buildbot/chromium.mac.json
+++ b/testing/buildbot/chromium.mac.json
@@ -135,6 +135,9 @@
         "test": "gpu_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "jingle_unittests"
       },
       {
@@ -340,6 +343,9 @@
         "test": "ipc_tests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "jingle_unittests"
       },
       {
@@ -557,6 +563,9 @@
         "test": "ipc_tests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "jingle_unittests"
       },
       {
@@ -774,6 +783,9 @@
         "test": "ipc_tests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "jingle_unittests"
       },
       {
@@ -992,6 +1004,9 @@
         "test": "ipc_tests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "jingle_unittests"
       },
       {