Clean VM thread shutdown:

runtime/vm/service_isolate.h

 // Copyright (c) 2013, 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.
 
 #ifndef VM_SERVICE_ISOLATE_H_
 #define VM_SERVICE_ISOLATE_H_
 
 #include "include/dart_api.h"
 
 #include "vm/allocation.h"
@@ skipping 14 matching lines @@
 
   static Dart_Port WaitForLoadPort();
   static Dart_Port LoadPort();
 
   static void Run();
   static bool SendIsolateStartupMessage();
   static bool SendIsolateShutdownMessage();
   static void SendServiceExitMessage();
   static void Shutdown();
 
+ private:
+  static void KillServiceIsolate();
+
  protected:
   static void SetServicePort(Dart_Port port);
   static void SetServiceIsolate(Isolate* isolate);
   static void SetLoadPort(Dart_Port port);
   static void ConstructExitMessageAndCache(Isolate* isolate);
   static void FinishedExiting();
   static void FinishedInitializing();
   static void MaybeInjectVMServiceLibrary(Isolate* isolate);
   static Dart_IsolateCreateCallback create_callback() {
     return create_callback_;
@@ skipping 15 matching lines @@
   static Dart_Port origin_;
 
   friend class Dart;
   friend class RunServiceTask;
   friend class ServiceIsolateNatives;
 };
 
 }  // namespace dart
 
 #endif  // VM_SERVICE_ISOLATE_H_