Initial support to test.dart for running precompiler tests on android devices

tools/test.dart

 #!/usr/bin/env dart
 // Copyright (c) 2013, 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 test suite.  This suite is used
  * to test:
  *
  *     1. the dart vm
@@ skipping 39 matching lines @@
         }, onDone: completer.complete);
   } else {
     completer.complete();
   }
   return completer.future;
 }
 
 void main(List<String> arguments) {
   // This script is in [dart]/tools.
   TestUtils.setDartDirUri(Platform.script.resolve('..'));
-  _deleteTemporaryDartDirectories().then((_) {
+  _deleteTemporaryDartDirectories().then((_) async {
     var optionsParser = new TestOptionsParser();
     var configurations = optionsParser.parse(arguments);
     if (configurations != null && configurations.length > 0) {
-      testConfigurations(configurations);
+      await testConfigurations(configurations);

[Bill Hesse, 2016/04/27 12:22:31]

What does this even do?  We aren't doing anything with the returned future.

Couldn't this just be replaced with "return
testConfigurations(configurations);", since .then handles a returned future?

[kustermann, 2016/04/27 13:25:08]

It runs all the tests. So it makes sense that it returns a future.
I think it makes it clearer that we wait until testing all configurations is
done.

     }
   });
 }