Add linux_chromium_tsan_rel_ng to 10% of CQs.

infra/config/cq.cfg

Index: infra/config/cq.cfg
diff --git a/infra/config/cq.cfg b/infra/config/cq.cfg
index 5a494cee5630e8eb0be99a7632e440e6f2680b36..549191bf2d3b3678d29ca72d6aac5cba624d32a5 100644
--- a/infra/config/cq.cfg
+++ b/infra/config/cq.cfg
@@ -57,6 +57,10 @@ verifiers {
         experiment_percentage: 100
       }
       builders { name: "linux_chromium_rel_ng" }
+      builders {
+        name: "linux_chromium_tsan_rel_ng"
+        experiment_percentage: 10
+      }
     }
     buckets {
       name: "master.tryserver.chromium.mac"