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

tools/test.dart

Index: tools/test.dart
diff --git a/tools/test.dart b/tools/test.dart
index bbfdf258cfedc62378168386c7bea12fdf7aa3cd..48a7d082e0b46a1179d56afd196131ee902807ea 100755
--- a/tools/test.dart
+++ b/tools/test.dart
@@ -57,11 +57,11 @@ Future _deleteTemporaryDartDirectories() {
 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.

     }
   });
 }