cq: enable more LUCI try builders

infra/config/cq.cfg

Index: infra/config/cq.cfg
diff --git a/infra/config/cq.cfg b/infra/config/cq.cfg
index 7cfb95a6257e5c84a4a79ab45b083cf59f61957c..903732636d2964eeb20afb7202db619eb58f8a78 100644
--- a/infra/config/cq.cfg
+++ b/infra/config/cq.cfg
@@ -34,9 +34,19 @@ verifiers {
   try_job {
     buckets {
       name: "luci.chromium.try"
+      # Builders in this bucket are defined in
+      # https://chromium.googlesource.com/chromium/src/+/infra/config/cr-buildbucket.cfg
       builders {
         name: "LUCI linux_chromium_rel_ng"
-        experiment_percentage: 1
+        experiment_percentage: 5
+      }
+      builders {
+        name: "LUCI mac_chromium_rel_ng"
+        experiment_percentage: 5
+      }
+      builders {
+        name: "LUCI win_chromium_rel_ng"
+        experiment_percentage: 5
       }
     }
     buckets {