Add support for asynchronous event notification to the observatory.

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 8d0587fcee202c4b6b6ad060690daf55f52f496d..18ab3ee02f862a5cc27bc136bbfb3a8abc20e0cf 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -978,11 +978,11 @@ void Isolate::PrintJSON(JSONStream* stream, bool ref) {
   // TODO(turnidge): Make the debugger support paused_on_start/exit.
   if (message_handler()->paused_on_start()) {
     ASSERT(debugger()->PauseEvent() == NULL);
-    DebuggerEvent pauseEvent(DebuggerEvent::kIsolateCreated);
+    DebuggerEvent pauseEvent(this, DebuggerEvent::kIsolateCreated);
     jsobj.AddProperty("pauseEvent", &pauseEvent);
   } else if (message_handler()->paused_on_exit()) {
     ASSERT(debugger()->PauseEvent() == NULL);
-    DebuggerEvent pauseEvent(DebuggerEvent::kIsolateShutdown);
+    DebuggerEvent pauseEvent(this, DebuggerEvent::kIsolateShutdown);
     jsobj.AddProperty("pauseEvent", &pauseEvent);
   } else if (debugger()->PauseEvent() != NULL) {
     jsobj.AddProperty("pauseEvent", debugger()->PauseEvent());