Simplify test_suite.dart.

tools/testing/dart/main.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// This file is the entrypoint of the Dart repository's custom test system.
 /// It is used to test:
 ///
 ///     1. The Dart VM
 ///     2. The dart2js compiler
 ///     3. The static analyzer
 ///     4. The Dart core library
 ///     5. Other standard dart libraries (DOM bindings, UI libraries,
 ///        IO libraries etc.)
 ///
 /// This script is normally invoked by test.py. (test.py finds the Dart VM and
 /// passes along all command line arguments to this script.)
 ///
 /// The command line args of this script are documented in "test_options.dart".
 /// They are printed when this script is run with "--help".
 ///
 /// The default test directory layout is documented in "test_suite.dart", above
 /// `factory StandardTestSuite.forDirectory`.
 import "dart:io";
 
 import "options.dart";
 import "test_configurations.dart";
-import "test_suite.dart";
+import 'utils.dart';
 
 /// Runs all of the tests specified by the given command line [arguments].
 void main(List<String> arguments) {
   // This script is in "<repo>/tools/testing/dart".
   TestUtils.setDartDirUri(Platform.script.resolve('../../..'));
 
   // Parse the command line arguments to a configuration.
   var parser = new OptionsParser();
   var configurations = parser.parse(arguments);
   if (configurations.isEmpty) return;
 
   // Run all of the configured tests.
   // TODO(26372): Ensure that all tasks complete and return a future from this
   // function.
   testConfigurations(configurations);
 }