Call shutdown callback before the isolate is destroyed

runtime/include/dart_api.h

 /*
  * Copyright (c) 2012, 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 INCLUDE_DART_API_H_
 #define INCLUDE_DART_API_H_
 
 /** \mainpage Dart Embedding API Reference
@@ skipping 648 matching lines @@
  * isolate was running when the exception was thrown.
  *
  * \param error The unhandled exception or error.  This handle's scope is
  *   only valid until the embedder returns from this callback.
  */
 typedef void (*Dart_IsolateUnhandledExceptionCallback)(Dart_Handle error);
 
 /**
  * An isolate shutdown callback function.
  *
- * This callback, provided by the embedder, is called after the vm
- * shuts down an isolate.  Since the isolate has been shut down, it is
- * not safe to enter the isolate or use it to run any Dart code.
+ * This callback, provided by the embedder, is called before the vm
+ * shuts down an isolate.  The isolate being shutdown will be the current
+ * isolate. It is safe to run Dart code.
  *
  * This function should be used to dispose of native resources that
  * are allocated to an isolate in order to avoid leaks.
  *
  * \param callback_data The same callback data which was passed to the
  *   isolate when it was created.
  *
  */
 typedef void (*Dart_IsolateShutdownCallback)(void* callback_data);
 
@@ skipping 1517 matching lines @@
  *
  * \param object An object.
  * \param peer A value to store in the peer field.
  *
  * \return Returns an error if 'object' is a subtype of Null, num, or
  *   bool.
  */
 DART_EXPORT Dart_Handle Dart_SetPeer(Dart_Handle object, void* peer);
 
 #endif  /* INCLUDE_DART_API_H_ */  /* NOLINT */