Make service protocol respect isolate lifecycle

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 4172327255161565a66b914e5e0008df5877e423..5ad47d357d4f2ef322118e413b90b4addbd0da65 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -1995,11 +1995,17 @@ void Isolate::PrintJSON(JSONStream* stream, bool ref) {
     ASSERT((debugger() == NULL) || (debugger()->PauseEvent() == NULL));
     ServiceEvent pause_event(this, ServiceEvent::kNone);
     jsobj.AddProperty("pauseEvent", &pause_event);
-  } else if (message_handler()->is_paused_on_start() ||
-             message_handler()->should_pause_on_start()) {
-    ASSERT((debugger() == NULL) || (debugger()->PauseEvent() == NULL));
-    ServiceEvent pause_event(this, ServiceEvent::kPauseStart);
-    jsobj.AddProperty("pauseEvent", &pause_event);
+  } else if (message_handler()->should_pause_on_start()) {
+    if (message_handler()->is_paused_on_start()) {
+      ASSERT((debugger() == NULL) || (debugger()->PauseEvent() == NULL));
+      ServiceEvent pause_event(this, ServiceEvent::kPauseStart);
+      jsobj.AddProperty("pauseEvent", &pause_event);
+    } else {
+      // Isolate is runnable but not paused on start.

[rmacnak, 2017/08/30 23:31:52]

// Some service clients get confused if they see NotRunnable -> Runnable ->
PausedAtStart. Treat Runnable+ShouldPauseOnStart as NotRunnable so they see
NonRunnable -> PausedAtStart.

[cbernaschina, 2017/08/30 23:53:57]

Done.

+      ASSERT((debugger() == NULL) || (debugger()->PauseEvent() == NULL));
+      ServiceEvent pause_event(this, ServiceEvent::kNone);
+      jsobj.AddProperty("pauseEvent", &pause_event);
+    }
   } else if (message_handler()->is_paused_on_exit() &&
              ((debugger() == NULL) || (debugger()->PauseEvent() == NULL))) {
     ServiceEvent pause_event(this, ServiceEvent::kPauseExit);