Enable swarming on filesystem_service_unittests.

BUG=606012

Review-Url: https://codereview.chromium.org/1914043002
Cr-Commit-Position: refs/heads/master@{#390212}

diff --git a/BUILD.gn b/BUILD.gn
index 66a1cc4..552e53d 100644
--- a/BUILD.gn
+++ b/BUILD.gn

@@ -655,7 +655,7 @@
       "//chrome/installer/util:strings",
       "//chrome/tools/convert_dict",
       "//components/constrained_window:unit_tests",
-      "//components/filesystem:unittests",
+      "//components/filesystem:filesystem_service_unittests",
       "//components/leveldb:leveldb_service_unittests",
       "//components/metrics:serialization",
       "//components/password_manager/content/renderer:browser_tests",