Tighten up a bunch of types in test.dart.

tools/testing/dart/package_testing_support.dart

Index: tools/testing/dart/package_testing_support.dart
diff --git a/tools/testing/dart/package_testing_support.dart b/tools/testing/dart/package_testing_support.dart
index d783895112c7280e58c5d8d4d630211a839ac7bd..d470663538494cd9cbbbbdcba19f6c9d3a0ec86d 100644
--- a/tools/testing/dart/package_testing_support.dart
+++ b/tools/testing/dart/package_testing_support.dart
@@ -10,10 +10,10 @@ import 'test_options.dart' show TestOptionsParser;
 
 import 'test_suite.dart' show TestUtils;
 
-main(List<String> arguments) {
+void main(List<String> arguments) {
   TestUtils.setDartDirUri(Uri.base);
-  List<Map> configurations = <Map>[];
-  for (String argument in arguments) {
+  var configurations = <Map>[];
+  for (var argument in arguments) {
     configurations.addAll(new TestOptionsParser().parse(argument.split(" ")));
   }
   testConfigurations(configurations);