Dart: Reorganize files

mojo/dart/unittests/embedder_tester/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.
 
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//testing/test.gni")
 
-group("test") {
+group("embedder_tester") {
   testonly = true
   deps = [
     ":dart_finalizer_unittests",
     ":dart_to_cpp_unittests",
     ":dart_unittests",
     ":dart_validation_unittests",
   ]
 }
 
 source_set("dart_controller_for_test") {
@@ skipping 74 matching lines @@
 
 test("dart_validation_unittests") {
   sources = [
     "validation_unittest.cc",
   ]
   deps = [
     ":dart_test",
     ":dart_test_deps",
   ]
 }