Generate an error for active connections when the HTTP client is shutdown

sdk/lib/io/http.dart

Index: sdk/lib/io/http.dart
diff --git a/sdk/lib/io/http.dart b/sdk/lib/io/http.dart
index bcfa93302b8f713c737c605b756584dec5068285..036ace319f0a1e2796ec011e487e1d6c49254510 100644
--- a/sdk/lib/io/http.dart
+++ b/sdk/lib/io/http.dart
@@ -830,9 +830,12 @@ abstract class HttpClient {
   set findProxy(String f(Uri url));
 
   /**
-   * Shutdown the HTTP client releasing all resources.
+   * Shutdown the HTTP client. If [force] is [:true:] any active
+   * connections will be terminated to immediately release all
+   * resources. If [force] is [:false:] the [:HttpClient:] will be

[Mads Ager (google), 2012/11/23 07:25:38]

Could we add a comment to make it explicit what happens with connections that
are not done when you force a client shutdown?

[Søren Gjesse, 2012/11/23 09:08:47]

It's already there, "If [force] is [:true:]..." above.

[Søren Gjesse, 2012/11/23 09:31:16]

Added more information on forced shutdown.

+   * kept alive until all active connections are done.
    */
-  void shutdown();
+  void shutdown({bool force: false});
 }