Call shutdown callback before the isolate is destroyed

runtime/vm/dart.cc

Index: runtime/vm/dart.cc
diff --git a/runtime/vm/dart.cc b/runtime/vm/dart.cc
index 300e5b31e75817fd6e61f19895f7121252861033..e4013740eed50ae16637af0bcb53b85f2d7dd375 100644
--- a/runtime/vm/dart.cc
+++ b/runtime/vm/dart.cc
@@ -210,12 +210,9 @@ RawError* Dart::InitializeIsolate(const uint8_t* snapshot_buffer, void* data) {
 }
 
 
-void Dart::ShutdownIsolate() {
+void Dart::RunShutdownCallback() {
   Isolate* isolate = Isolate::Current();
   void* callback_data = isolate->init_callback_data();
-  isolate->Shutdown();
-  delete isolate;
-
   Dart_IsolateShutdownCallback callback = Isolate::ShutdownCallback();
   if (callback != NULL) {
     (callback)(callback_data);
@@ -223,6 +220,13 @@ void Dart::ShutdownIsolate() {
 }
 
 
+void Dart::ShutdownIsolate() {
+  Isolate* isolate = Isolate::Current();
+  isolate->Shutdown();
+  delete isolate;
+}
+
+
 uword Dart::AllocateReadOnlyHandle() {
   ASSERT(Isolate::Current() == Dart::vm_isolate());
   ASSERT(predefined_handles_ != NULL);