Distinguish internal kill messages from user-initiated kill messages.

runtime/vm/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_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/atomic.h"
@@ skipping 107 matching lines @@
   enum LibMsgId {
     kPauseMsg = 1,
     kResumeMsg = 2,
     kPingMsg = 3,
     kKillMsg = 4,
     kAddExitMsg = 5,
     kDelExitMsg = 6,
     kAddErrorMsg = 7,
     kDelErrorMsg = 8,
     kErrorFatalMsg = 9,
-    kInterruptMsg = 10,
+
+    // Internal message ids.
+    kInterruptMsg = 10,     // Break in the debugger.
+    kInternalKillMsg = 11,  // Like kill, but does not run exit listeners, etc.
   };
   // The different Isolate API message priorities for ping and kill messages.
   enum LibMsgPriority {
     kImmediateAction = 0,
     kBeforeNextEventAction = 1,
     kAsEventAction = 2
   };
 
   ~Isolate();
 
@@ skipping 1008 matching lines @@
   uint8_t* serialized_message_;
   intptr_t serialized_message_len_;
   Isolate::Flags isolate_flags_;
   bool paused_;
   bool errors_are_fatal_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_