Convert Mojo tests to use swarming.

mojo/public/js/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 source_set("js") {
   sources = [
     "constants.cc",
     "constants.h",
   ]
 }
+
+group("bindings") {
+  data = [
+    "bindings.js",
+    "buffer.js",
+    "codec.js",
+    "connection.js",
+    "connector.js",
+    "constants.cc",
+    "constants.h",
+    "core.js",
+    "router.js",
+    "support.js",
+    "threading.js",
+    "unicode.js",
+    "validator.js",
+  ]
+}
+
+group("tests") {
+  testonly = true
+
+  data = [
+    "codec_unittests.js",
+    "core_unittests.js",
+    "struct_unittests.js",
+    "test/validation_test_input_parser.js",
+    "union_unittests.js",
+    "validation_unittests.js",
+    "//mojo/public/interfaces/bindings/tests/data/validation/",
+  ]
+  public_deps = [
+    ":bindings",
+  ]
+}