Add built-in root certificates to dart:io SecureSocket.

tests/standalone/io/secure_no_builtin_roots_test.dart

+// Copyright (c) 2012, 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.
+
+import "dart:io";
+import "dart:uri";
+import "dart:isolate";
+
+void testGoogleUrl() {
+  ReceivePort keepalivePort = new ReceivePort();
+  HttpClient client = new HttpClient();
+
+  void testUrl(String url) {
+    var requestUri = new Uri.fromString(url);
+    var conn = client.getUrl(requestUri);
+
+    conn.onRequest = (HttpClientRequest request) {
+      request.outputStream.close();
+    };
+    conn.onResponse = (HttpClientResponse response) {
+      Expect.fail("Https connection unexpectedly succeeded");
+    };
+    conn.onError = (error) {
+      Expect.isTrue(error is SocketIOException);
+      keepalivePort.close();
+    };
+  }
+
+  testUrl('https://www.google.com');
+}
+
+void InitializeSSL() {
+  // If the built-in root certificates aren't loaded, the connection
+  // should signal an error.
+  SecureSocket.initialize(useBuiltinRoots: false);
+}
+
+void main() {
+  InitializeSSL();
+  testGoogleUrl();
+}