Move service into VM

runtime/vm/service/running_isolates.dart

Index: runtime/vm/service/running_isolates.dart
diff --git a/runtime/bin/vmservice/running_isolates.dart b/runtime/vm/service/running_isolates.dart
similarity index 93%
rename from runtime/bin/vmservice/running_isolates.dart
rename to runtime/vm/service/running_isolates.dart
index db93d089c5d0354599a758d067fa0d1e03bad7ba..e8e00449a4002adecb18a02fb07a529e76857899 100644
--- a/runtime/bin/vmservice/running_isolates.dart
+++ b/runtime/vm/service/running_isolates.dart
@@ -10,16 +10,13 @@ class RunningIsolates implements MessageRouter {
   RunningIsolates();
 
   void isolateStartup(int portId, SendPort sp, String name) {
-    if (isolates[portId] != null) {
-      throw new StateError('Duplicate isolate startup.');
-    }
     var ri = new RunningIsolate(portId, sp, name);
     isolates[portId] = ri;
   }
 
   void isolateShutdown(int portId, SendPort sp) {
     if (isolates[portId] == null) {
-      throw new StateError('Unknown isolate.');
+      return;
     }
     isolates.remove(portId);
   }