Convert mojo_public_bindings_unittests to run exclusively on Swarming

testing/buildbot/chromium.fyi.json

Index: testing/buildbot/chromium.fyi.json
diff --git a/testing/buildbot/chromium.fyi.json b/testing/buildbot/chromium.fyi.json
index 8173fc10e1adc93b136e0047b39d826678aca755..d8b9b308e9fc2ce3ed99cd5299837d1880b53059 100644
--- a/testing/buildbot/chromium.fyi.json
+++ b/testing/buildbot/chromium.fyi.json
@@ -436,6 +436,9 @@
         "test": "mojo_common_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "mojo_public_bindings_unittests"
       },
       {
@@ -747,6 +750,9 @@
         "test": "mojo_common_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "mojo_public_bindings_unittests"
       },
       {
@@ -922,6 +928,9 @@
         "test": "mojo_common_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "mojo_public_bindings_unittests"
       },
       {
@@ -3318,6 +3327,9 @@
         "test": "mojo_common_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "mojo_public_bindings_unittests"
       },
       {
@@ -3785,6 +3797,9 @@
         "test": "mojo_common_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "mojo_public_bindings_unittests"
       },
       {