Fix some service protocol isolate lifecycle races

runtime/observatory/lib/src/service/object.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.
 
 part of service;
 
 // Some value smaller than the object ring, so requesting a large array
 // doesn't result in an expired ref because the elements lapped it in the
 // object ring.
 const int kDefaultFieldLimit = 100;
@@ skipping 1494 matching lines @@
 
       case ServiceEvent.kBreakpointRemoved:
         _removeBreakpoint(event.breakpoint);
         break;
 
       case ServiceEvent.kPauseStart:
       case ServiceEvent.kPauseExit:
       case ServiceEvent.kPauseBreakpoint:
       case ServiceEvent.kPauseInterrupted:
       case ServiceEvent.kPauseException:
+      case ServiceEvent.kNone:
       case ServiceEvent.kResume:
         assert((pauseEvent == null) ||
                !event.timestamp.isBefore(pauseEvent.timestamp));
         pauseEvent = event;
         _updateRunState();
         break;
 
       case ServiceEvent.kGraph:
         _loadHeapSnapshot(event);
         break;
@@ skipping 289 matching lines @@
   static const kIsolateStart           = 'IsolateStart';
   static const kIsolateRunnable        = 'IsolateRunnable';
   static const kIsolateExit            = 'IsolateExit';
   static const kIsolateUpdate          = 'IsolateUpdate';
   static const kServiceExtensionAdded  = 'ServiceExtensionAdded';
   static const kPauseStart             = 'PauseStart';
   static const kPauseExit              = 'PauseExit';
   static const kPauseBreakpoint        = 'PauseBreakpoint';
   static const kPauseInterrupted       = 'PauseInterrupted';
   static const kPauseException         = 'PauseException';
+  static const kNone                   = 'None';
   static const kResume                 = 'Resume';
   static const kBreakpointAdded        = 'BreakpointAdded';
   static const kBreakpointResolved     = 'BreakpointResolved';
   static const kBreakpointRemoved      = 'BreakpointRemoved';
   static const kGraph                  = '_Graph';
   static const kGC                     = 'GC';
   static const kInspect                = 'Inspect';
   static const kDebuggerSettingsUpdate = '_DebuggerSettingsUpdate';
   static const kConnectionClosed       = 'ConnectionClosed';
   static const kLogging                = '_Logging';
@@ skipping 22 matching lines @@
   @observable String extensionKind;
   @observable Map extensionData;
 
   int chunkIndex, chunkCount, nodeCount;
 
   @observable bool get isPauseEvent {
     return (kind == kPauseStart ||
             kind == kPauseExit ||
             kind == kPauseBreakpoint ||
             kind == kPauseInterrupted ||
-            kind == kPauseException);
+            kind == kPauseException ||
+            kind == kNone);
   }
 
   void _update(ObservableMap map, bool mapIsRef) {
     _loaded = true;
     _upgradeCollection(map, owner);
 
     assert(map['isolate'] == null || owner == map['isolate']);
     timestamp =
         new DateTime.fromMillisecondsSinceEpoch(map['timestamp']);
     kind = map['kind'];
@@ skipping 2134 matching lines @@
     var v = list[i];
     if ((v is ObservableMap) && _isServiceMap(v)) {
       list[i] = owner.getFromMap(v);
     } else if (v is ObservableList) {
       _upgradeObservableList(v, owner);
     } else if (v is ObservableMap) {
       _upgradeObservableMap(v, owner);
     }
   }
 }