infra: add buildbucket-swarming trybots as 100% experiment

config/cq.cfg

Index: config/cq.cfg
diff --git a/config/cq.cfg b/config/cq.cfg
index 2b04fe14ce3f1c13d347ea367a0fb16d03601278..16ecf9dcd084b9b9d0b28d27395049e06845931f 100644
--- a/config/cq.cfg
+++ b/config/cq.cfg
@@ -18,6 +18,25 @@ verifiers {
   }
   try_job {
     buckets {
+      name: "chromium.buildbucket.swarming"
+      builders {
+        name: "infra_presubmit"
+        experiment_percentage: 100
+      }
+      builders {
+        name: "infra_linux64"
+        experiment_percentage: 100
+      }
+      builders {
+        name: "infra_mac"
+        experiment_percentage: 100
+      }
+      builders {
+        name: "infra_win"
+        experiment_percentage: 100
+      }
+    }
+    buckets {
       name: "tryserver.infra",
       builders {
         name: "Infra Presubmit"