New implementation of {,Linked}Hash{Set,Map}.

sdk/lib/io/http_impl.dart

Index: sdk/lib/io/http_impl.dart
diff --git a/sdk/lib/io/http_impl.dart b/sdk/lib/io/http_impl.dart
index efa341c3d305ba48c50372cc1835fb6930b7c868..a8334da970c126ca0fdba80d23f5dfe42049c8bd 100644
--- a/sdk/lib/io/http_impl.dart
+++ b/sdk/lib/io/http_impl.dart
@@ -1917,14 +1917,15 @@ class _HttpClient implements HttpClient {
 
   void shutdown({bool force: false}) {
     if (force) _closeQueue.shutdown();
-    _openSockets.forEach((String key, Queue<_SocketConnection> connections) {
+    new Map.from(_openSockets).forEach(
+        (String key, Queue<_SocketConnection> connections) {
       while (!connections.isEmpty) {
         _SocketConnection socketConn = connections.removeFirst();
         socketConn._socket.close();
       }
     });
     if (force) {
-      _activeSockets.forEach((_SocketConnection socketConn) {
+      _activeSockets.toList().forEach((_SocketConnection socketConn) {
         socketConn._httpClientConnection._onClientShutdown();
         socketConn._close();
       });