Remove AsyncError with Expando.

sdk/lib/io/secure_socket.dart

Index: sdk/lib/io/secure_socket.dart
diff --git a/sdk/lib/io/secure_socket.dart b/sdk/lib/io/secure_socket.dart
index c5fe3c2290befce7aa4df18329b5179193a77414..88f51c58b49bcb9b22da7914f47227f27743402f 100644
--- a/sdk/lib/io/secure_socket.dart
+++ b/sdk/lib/io/secure_socket.dart
@@ -288,7 +288,7 @@ class _RawSecureSocket extends Stream<RawSocketEvent>
   }
 
   StreamSubscription listen(void onData(RawSocketEvent data),
-                            {void onError(AsyncError error),
+                            {void onError(error),
                              void onDone(),
                              bool unsubscribeOnError}) {
     if (_writeEventsEnabled) {
@@ -464,8 +464,7 @@ class _RawSecureSocket extends Stream<RawSocketEvent>
   // up handlers to flush the pipeline when possible.
   int write(List<int> data, [int offset, int bytes]) {
     if (_closedWrite) {
-      _controller.addError(new AsyncError(new SocketIOException(
-          "Writing to a closed socket")));
+      _controller.addError(new SocketIOException("Writing to a closed socket"));
       return 0;
     }
     if (_status != CONNECTED) return 0;
@@ -567,12 +566,9 @@ class _RawSecureSocket extends Stream<RawSocketEvent>
     _reportError(e, 'Error on underlying RawSocket');
   }
 
-  void _reportError(error, String message) {
+  void _reportError(e, String message) {
     // TODO(whesse): Call _reportError from all internal functions that throw.
-    var e;
-    if (error is AsyncError) {
-      e = error;
-    } else if (error is SocketIOException) {
+    if (e is SocketIOException) {
       e = new SocketIOException('$message (${error.message})', error.osError);
     } else if (error is OSError) {
       e = new SocketIOException(message, error);