DO NOT SUBMIT: Unix domain sockets. From CL 1061283003.

sdk/lib/io/socket.dart

Index: sdk/lib/io/socket.dart
diff --git a/sdk/lib/io/socket.dart b/sdk/lib/io/socket.dart
index a759598def0bc35786ffb83ada29ac917d265fdc..5516f00dae7ee7c4c00bc5532505360b2a5f9538 100644
--- a/sdk/lib/io/socket.dart
+++ b/sdk/lib/io/socket.dart
@@ -144,6 +144,13 @@ abstract class InternetAddress {
 }
 
 
+class UnixDomainAddress {
+  final String path;
+  bool get isLoopback => false;  // HACK.
+  UnixDomainAddress(this.path);
+}
+
+
 /**
  * A [NetworkInterface] represent an active network interface on the current
  * system. It contains a list of [InternetAddress]s, that's bound to the
@@ -759,7 +766,7 @@ abstract class RawDatagramSocket extends Stream<RawSocketEvent> {
 class SocketException implements IOException {
   final String message;
   final OSError osError;
-  final InternetAddress address;
+  final /* InternetAddress or UnixDomainAddress */ address;
   final int port;
 
   const SocketException(this.message, {this.osError, this.address, this.port});