Update the streams interfaces

runtime/bin/socket_impl.dart

Index: runtime/bin/socket_impl.dart
diff --git a/runtime/bin/socket_impl.dart b/runtime/bin/socket_impl.dart
index 585a4dfd06ad78a03ac484c58b7327a0f1908ccc..d578d04bb1e85f83aa74f54f1262a69874cdb8bb 100644
--- a/runtime/bin/socket_impl.dart
+++ b/runtime/bin/socket_impl.dart
@@ -277,14 +277,14 @@ class _Socket extends _SocketBase implements Socket {
   }
 
   InputStream get inputStream() {
-    if (_inputStream === null) {
+    if (_inputStream == null) {
       _inputStream = new SocketInputStream(this);
     }
     return _inputStream;
   }
 
   OutputStream get outputStream() {
-    if (_outputStream === null) {
+    if (_outputStream == null) {
       _outputStream = new SocketOutputStream(this);
     }
     return _outputStream;