Merge IO v2 branch to bleeding edge

tests/standalone/io/secure_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 keepAlive = new ReceivePort();
-  HttpClient client = new HttpClient();
-
-  void testUrl(String url) {
-    var requestUri = Uri.parse(url);
-    var conn = client.getUrl(requestUri);
-
-    conn.onRequest = (HttpClientRequest request) {
-      request.outputStream.close();
-    };
-    conn.onResponse = (HttpClientResponse response) {
-      Expect.isTrue(response.statusCode < 500);
-      Expect.isTrue(response.statusCode != 404);
-      response.inputStream.onData = () {
-        response.inputStream.read();
-      };
-      response.inputStream.onClosed = () {
-        client.shutdown();
-        keepAlive.close();
-      };
-    };
-    conn.onError = (error) => Expect.fail("Unexpected IO error $error");
-  }
-
-  testUrl('https://www.google.com');
-}
-
-void InitializeSSL() {
-  SecureSocket.initialize();
-}
-
-void main() {
-  InitializeSSL();
-  testGoogleUrl();
-}