Convert mojo_public_bindings_unittests to run exclusively on Swarming

testing/buildbot/chromium.linux.json

Index: testing/buildbot/chromium.linux.json
diff --git a/testing/buildbot/chromium.linux.json b/testing/buildbot/chromium.linux.json
index 3710c31d57f78dc092e8ad83abf07dfc013cf5d6..4004bcd37fbac14f32e9c1f432fdff1781d58e06 100644
--- a/testing/buildbot/chromium.linux.json
+++ b/testing/buildbot/chromium.linux.json
@@ -25,6 +25,9 @@
         "test": "mojo_public_application_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "mojo_public_bindings_unittests"
       },
       {
@@ -686,6 +689,9 @@
         "test": "mojo_common_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "mojo_public_bindings_unittests"
       },
       {
@@ -1019,6 +1025,9 @@
         "test": "mojo_common_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "mojo_public_bindings_unittests"
       },
       {
@@ -1342,6 +1351,9 @@
         "test": "mojo_common_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "mojo_public_bindings_unittests"
       },
       {