Remove some prototype code that snuck into one of my commits.

runtime/lib/isolate_patch.dart

Index: runtime/lib/isolate_patch.dart
diff --git a/runtime/lib/isolate_patch.dart b/runtime/lib/isolate_patch.dart
index 41389a5a3f687004786d06d26945dd54bee05d22..a98bb5a052f6d855e324ea0d53d6c70f1d7e4efc 100644
--- a/runtime/lib/isolate_patch.dart
+++ b/runtime/lib/isolate_patch.dart
@@ -130,8 +130,6 @@ class _RawReceivePortImpl implements RawReceivePort {
     return sendPort.hashCode;
   }
 
-  Uri get remotePortUri => new Uri.https('localhost', '55');
-
   /**** Internal implementation details ****/
   _get_id() native "RawReceivePortImpl_get_id";
   _get_sendport() native "RawReceivePortImpl_get_sendport";