Add Proces owner of socket and fix printing of non-network sockets

runtime/bin/service_object_patch.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 
 final Map _servicePathMap = {
   'http' : {
     'servers' : _httpServersServiceObject,
   },
   'sockets' : _socketsServiceObject,
   'websockets' : _webSocketsServiceObject,
   'file' : {
     'randomaccessfiles' : _randomAccessFilesServiceObject
   },
   'processes' : _processesServiceObject,
 };
 
 String _serviceObjectHandler(List<String> paths,
                              List<String> keys,
                              List<String> values) {
   assert(keys.length == values.length);
-  badPath() {
-    throw "Invalid path '${paths.join("/")}'";
-  }
   if (paths.isEmpty) {
     return JSON.encode(_ioServiceObject());
   }
   int i = 0;
   var current = _servicePathMap;
   do {
     current = current[paths[i]];
     i++;
   } while (i < paths.length && current is Map);
   if (current is! Function) {
-    badPath();
+    return JSON.encode(_makeServiceError('Unrecognized path'));
   }
   var query = new Map();
   for (int i = 0; i < keys.length; i++) {
     query[keys[i]] = values[i];
   }
   return JSON.encode(current(paths.sublist(i)));
 }
 
+Map _makeServiceError(String message, [String kind]) {
+  var error = {
+    'type': 'Error',
+    'id': '',
+    'message': message,
+  };
+  if (kind != null) {
+    error['kind'] = kind;
+  }
+  return error;
+}
+
 Map _ioServiceObject() {
   return {
     'id': 'io',
     'type': 'IO',
     'name': 'io',
     'user_name': 'io',
   };
 }
 
 Map _httpServersServiceObject(args) {
@@ skipping 68 matching lines @@
     }
     return process._toJSON(false);
   }
   return {
     'id': 'io/processes',
     'type': 'ProcessList',
     'members': _ProcessImpl._processes.values
         .map((p) => p._toJSON(true)).toList(),
   };
 }