Fix Observatory double connection in clean browser

runtime/observatory/lib/src/repositories/target.dart

 // Copyright (c) 2016, 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.
 
 part of repositories;
 
 typedef bool IsConnectedVMTargetDelegate(Target);
 
 class TargetChangeEvent implements M.TargetChangeEvent {
   final TargetRepository repository;
@@ skipping 13 matching lines @@
   final IsConnectedVMTargetDelegate _isConnectedVMTarget;
 
   factory TargetRepository(IsConnectedVMTargetDelegate isConnectedVMTarget) {
     var controller = new StreamController<TargetChangeEvent>();
     var stream = controller.stream.asBroadcastStream();
     return new TargetRepository._(isConnectedVMTarget, controller, stream);
   }
 
   TargetRepository._(this._isConnectedVMTarget, this._onChange, this.onChange) {
     _restore();
+    final defaultAddress = _networkAddressOfDefaultTarget();
+    var defaultTarget = find(defaultAddress);
     // Add the default address if it doesn't already exist.
-    if (find(_networkAddressOfDefaultTarget()) == null) {
-      add(_networkAddressOfDefaultTarget());
+    if (defaultTarget == null) {
+      defaultTarget = new SC.WebSocketVMTarget(defaultAddress);
+      _list.insert(0, defaultTarget);
     }
     // Set the current target to the default target.
-    current = find(_networkAddressOfDefaultTarget());
+    current = defaultTarget;
   }
 
   void add(String address) {
     if (find(address) != null) {
       return;
     }
     _list.insert(0, new SC.WebSocketVMTarget(address));
     _onChange.add(new TargetChangeEvent(this));
     _store();
   }
@@ skipping 57 matching lines @@
     if (!identical(1, 1.0)) {
       // Dartium, assume we are developing.
       return 'ws://127.0.0.1:8181/ws';
     }
     Uri serverAddress = Uri.parse(window.location.toString());
     return 'ws://${serverAddress.authority}${serverAddress.path}ws';
   }
 
   bool isConnectedVMTarget(M.Target target) => _isConnectedVMTarget(target);
 }