Add .address to [Raw]ServerSocket and HttpServer.

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 31f6b9739f5aeabd7402fd8c7957983c281ba1a0..ee63d1a025ffa7eeab173397b9c8d135adea2ae7 100644
--- a/sdk/lib/io/http.dart
+++ b/sdk/lib/io/http.dart
@@ -186,6 +186,13 @@ abstract class HttpServer implements Stream<HttpRequest> {
   int get port;
 
   /**
+   * Returns the address that the server is listening on. This can be
+   * used to get the actual address used, when the address is fetched by
+   * a lookup from a hostname.
+   */
+  InternetAddress get address;
+
+  /**
    * Sets the timeout, in seconds, for sessions of this [HttpServer].
    * The default timeout is 20 minutes.
    */