Fix some service protocol isolate lifecycle races

runtime/observatory/lib/src/elements/debugger.dart

Index: runtime/observatory/lib/src/elements/debugger.dart
diff --git a/runtime/observatory/lib/src/elements/debugger.dart b/runtime/observatory/lib/src/elements/debugger.dart
index 6595447668fe6edf0c83f9110a3fa778b57b4aae..406f75a02765cd572633852308974e490e0844b7 100644
--- a/runtime/observatory/lib/src/elements/debugger.dart
+++ b/runtime/observatory/lib/src/elements/debugger.dart
@@ -1524,7 +1524,9 @@ class ObservatoryDebugger extends Debugger {
   }
 
   void _reportPause(ServiceEvent event) {
-    if (event.kind == ServiceEvent.kPauseStart) {
+    if (event.kind == ServiceEvent.kPauseUntilRunnable) {

[turnidge, 2016/03/03 17:15:01]

I'm debating this name a bit.

It could just be ServiceEvent.kNotRunnable or ServiceEvent.kPauseNotRunnable or
maybe even ServiceEvent.kNone (no event ever sent).

[Cutch, 2016/03/03 19:22:00]

ServiceEvent.kNone.

Done.

+      console.print("Paused until embedder makes the isolate runnable.");
+    } else if (event.kind == ServiceEvent.kPauseStart) {
       console.print(
           "Paused at isolate start "
           "(type 'continue' [F7] or 'step' [F10] to start the isolate')");