Refactor the close and error handling of HTTP connections

tests/standalone/src/io/HttpServerSocketTest.dart

Index: tests/standalone/src/io/HttpServerSocketTest.dart
diff --git a/tests/standalone/src/io/HttpServerSocketTest.dart b/tests/standalone/src/io/HttpServerSocketTest.dart
index 1339c9b22221e626d8d439b94d856e9a06d606d8..d25481010c287fa91063efc7f802f83e90a38745 100644
--- a/tests/standalone/src/io/HttpServerSocketTest.dart
+++ b/tests/standalone/src/io/HttpServerSocketTest.dart
@@ -9,7 +9,7 @@ class ExpectedDataOutputStream implements OutputStream {
   ExpectedDataOutputStream(List<int> this._data,
                            int this._cutoff,
                            bool this._closeAsError,
-                           SocketImpl this._socket);
+                           SocketMock this._socket);
 
   void set onNoPendingWrites(void callback()) {
     _onNoPendingWrites = callback;
@@ -49,7 +49,7 @@ class ExpectedDataOutputStream implements OutputStream {
   int _written = 0;
   int _cutoff;
   bool _closeAsError;
-  SocketImpl _socket;
+  SocketMock _socket;
 }
 
 class SocketMock implements Socket {