Fix sdk/lib/io errors found by the analyzer.

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;
 
 class _HttpIncoming extends Stream<List<int>> {
   final int _transferLength;
   final Completer _dataCompleter = new Completer();
   Stream<List<int>> _stream;
@@ skipping 442 matching lines @@
 
   void writeCharCode(int charCode) {
     _dataSink.writeCharCode(charCode);
   }
 
   void add(List<int> data) {
     if (data.length == 0) return;
     _dataSink.add(data);
   }
 
-  void addError(error) {
-    _dataSink.addError(error);
+  void addError(error, [StackTrace stackTrace]) {
+    _dataSink.addError(error, stackTrace);
   }
 
   Future<T> addStream(Stream<List<int>> stream) {
     return _dataSink.addStream(stream);
   }
 
   Future close() {
     return _dataSink.close();
   }
 
@@ skipping 1762 matching lines @@
   void writeln([Object obj = ""]) => _socket.writeln(obj);
 
   void writeCharCode(int charCode) => _socket.writeCharCode(charCode);
 
   void writeAll(Iterable objects, [String separator = ""]) {
     _socket.writeAll(objects, separator);
   }
 
   void add(List<int> bytes) => _socket.add(bytes);
 
-  void addError(error) => _socket.addError(error);
+  void addError(error, [StackTrace stackTrace]) =>
+      _socket.addError(error, stackTrace);
 
   Future<Socket> addStream(Stream<List<int>> stream) {
     return _socket.addStream(stream);
   }
 
   void destroy() => _socket.destroy();
 
   Future close() => _socket.close();
 
   Future<Socket> get done => _socket.done;
@@ skipping 253 matching lines @@
   final Uri 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)';
 }