Fix static warnings introduced by library cleanup.

sdk/lib/io/http_impl.dart

 // Copyright (c) 2013, 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.
 
 part of dart.io;
 
 const int _HEADERS_BUFFER_SIZE = 8 * 1024;
 
 class _HttpIncoming extends Stream<List<int>> {
   final int _transferLength;
@@ skipping 152 matching lines @@
 
   _HttpClientResponse(_HttpIncoming _incoming, this._httpRequest,
                       this._httpClient) : super(_incoming) {
     // Set uri for potential exceptions.
     _incoming.uri = _httpRequest.uri;
   }
 
   int get statusCode => _incoming.statusCode;
   String get reasonPhrase => _incoming.reasonPhrase;
 
-  X509Certificate get certificate =>
-    _httpRequest._httpClientConnection._socket.peerCertificate;
+  X509Certificate get certificate {
+    // The peerCertificate isn't on a plain socket, so cast to dynamic.
+    var socket = _httpRequest._httpClientConnection._socket;
+    return socket.peerCertificate;
+  }
 
   List<Cookie> get cookies {
     if (_cookies != null) return _cookies;
     _cookies = new List<Cookie>();
     List<String> values = headers[HttpHeaders.SET_COOKIE];
     if (values != null) {
       values.forEach((value) {
         _cookies.add(new Cookie.fromSetCookieValue(value));
       });
     }
@@ skipping 2357 matching lines @@
   const _RedirectInfo(this.statusCode, this.method, this.location);
 }
 
 String _getHttpVersion() {
   var version = Platform.version;
   // Only include major and minor version numbers.
   int index = version.indexOf('.', version.indexOf('.') + 1);
   version = version.substring(0, index);
   return 'Dart/$version (dart:io)';
 }