Fix background compilation issues when creating snapshots.

runtime/vm/isolate.cc

 // 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.
 
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 1506 matching lines @@
 #define ISOLATE_METRIC_PRINT(type, variable, name, unit)                       \
   THR_Print("%s\n", metric_##variable##_.ToString());
 
     ISOLATE_METRIC_LIST(ISOLATE_METRIC_PRINT);
 #undef ISOLATE_METRIC_PRINT
     THR_Print("\n");
   }
 }
 
 
+void Isolate::StopBackgroundCompiler() {
+  // Wait until all background compilation has finished.
+  if (background_compiler_ != NULL) {
+    BackgroundCompiler::Stop(background_compiler_);
+  }
+}
+
+
 void Isolate::Shutdown() {
   ASSERT(this == Isolate::Current());
-  // Wait until all background compilation has finished.
-  if (background_compiler_ != NULL) {
-    BackgroundCompiler::Stop(background_compiler_);
-  }
+  StopBackgroundCompiler();
 
 #if defined(DEBUG)
   if (heap_ != NULL) {
     // The VM isolate keeps all objects marked.
     heap_->Verify(this == Dart::vm_isolate() ? kRequireMarked : kForbidMarked);
   }
 #endif  // DEBUG
 
   Thread* thread = Thread::Current();
 
@@ skipping 1094 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart