Increase the default test timeout for scheduled tests on Windows.

pkg/scheduled_test/test/scheduled_test_test.dart

Index: pkg/scheduled_test/test/scheduled_test_test.dart
diff --git a/pkg/scheduled_test/test/scheduled_test_test.dart b/pkg/scheduled_test/test/scheduled_test_test.dart
index b3c8477dd576ef1ff7cbfe79d898e9cdb2625177..b1c0acb985426cbd9c1fa24c57996ee0b6ca496b 100644
--- a/pkg/scheduled_test/test/scheduled_test_test.dart
+++ b/pkg/scheduled_test/test/scheduled_test_test.dart
@@ -5,6 +5,7 @@
 library scheduled_test_test;
 
 import 'dart:async';
+import 'dart:io';
 
 import 'package:scheduled_test/scheduled_test.dart';
 import 'package:scheduled_test/src/mock_clock.dart' as mock_clock;
@@ -13,6 +14,12 @@ import 'metatest.dart';
 import 'utils.dart';
 
 void main() {
+  metaSetUp(() {
+    // The windows bots are very slow, so we increase the default timeout.
+    if (Platform.operatingSystem != "windows") return;
+    currentSchedule.timeout = new Duration(seconds: 10);
+  });
+
   expectTestsPass('a scheduled test with a correct synchronous expectation '
       'should pass', () {
     test('test', () {