Support a @Timeout annotation.

test/runner/runner_test.dart

 // Copyright (c) 2015, 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.
 
 @TestOn("vm")
 
 import 'dart:io';
 import 'dart:math' as math;
 
 import 'package:path/path.dart' as p;
@@ skipping 310 matching lines @@
     });
   });
 
   test("runs tests even when a file fails to load", () {
     new File(p.join(_sandbox, "test.dart")).writeAsStringSync(_success);
     var result = _runUnittest(["test.dart", "nonexistent.dart"]);
     expect(result.stdout, contains("+1 -1: Some tests failed."));
     expect(result.exitCode, equals(1));
   });
 
+  test("respects top-level @Timeout declarations", () {
+    new File(p.join(_sandbox, "test.dart")).writeAsStringSync('''
+@Timeout(const Duration(seconds: 0))
+
+import 'dart:async';
+
+import 'package:test/test.dart';
+
+void main() {
+  test("timeout", () {});
+}
+''');
+
+    var result = _runUnittest(["test.dart"]);
+    expect(result.stdout, contains("Test timed out after 0 seconds."));
+    expect(result.stdout, contains("-1: Some tests failed."));
+  });
+
   group("flags:", () {
     test("with the --color flag, uses colors", () {
       new File(p.join(_sandbox, "test.dart")).writeAsStringSync(_failure);
       var result = _runUnittest(["--color", "test.dart"]);
       // This is the color code for red.
       expect(result.stdout, contains("\u001b[31m"));
     });
 
     group("with the --name flag,", () {
       test("selects tests with matching names", () {
@@ skipping 98 matching lines @@
       });
     });
   });
 }
 
 ProcessResult _runUnittest(List<String> args) =>
     runUnittest(args, workingDirectory: _sandbox);
 
 ProcessResult _runDart(List<String> args) =>
     runDart(args, workingDirectory: _sandbox);