Add tools/ddbg_service.

runtime/bin/vmservice/observatory/lib/service_common.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.
 
 library service_common;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:typed_data';
 
@@ skipping 69 matching lines @@
 abstract class CommonWebSocketVM extends VM {
   final Completer _connected = new Completer();
   final Completer _disconnected = new Completer();
   final WebSocketVMTarget target;
   final Map<String, _WebSocketRequest> _delayedRequests =
         new Map<String, _WebSocketRequest>();
   final Map<String, _WebSocketRequest> _pendingRequests =
       new Map<String, _WebSocketRequest>();
   int _requestSerial = 0;
   bool _hasInitiatedConnect = false;
+  bool _hasFinishedConnect = false;
   Utf8Decoder _utf8Decoder = new Utf8Decoder();
 
   CommonWebSocket _webSocket;
 
   CommonWebSocketVM(this.target, this._webSocket) {
     assert(target != null);
   }
 
   void _notifyConnect() {
+    _hasFinishedConnect = true;
     if (!_connected.isCompleted) {
       Logger.root.info('WebSocketVM connection opened: ${target.networkAddress}');
       _connected.complete(this);
     }
   }
   Future get onConnect => _connected.future;
   void _notifyDisconnect() {
+    if (!_hasFinishedConnect) {
+      return;
+    }
     if (!_disconnected.isCompleted) {
       Logger.root.info('WebSocketVM connection error: ${target.networkAddress}');
       _disconnected.complete(this);
     }
   }
   Future get onDisconnect => _disconnected.future;
 
   void disconnect() {
     if (_hasInitiatedConnect) {
       _webSocket.close();
@@ skipping 160 matching lines @@
           'query': request.id
         }
       });
     } else {
       message = JSON.encode({'seq': serial, 'request': request.id});
     }
     // Send message.
     _webSocket.send(message);
   }
 }