Fix some service protocol isolate lifecycle races

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

 // Copyright (c) 2014, 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.
 
 library debugger_page_element;
 
 import 'dart:async';
 import 'dart:html';
 import 'dart:math';
 import 'observatory_element.dart';
@@ skipping 1506 matching lines @@
           'paused.');
     } else {
       console.printBold("Type 'set break-on-exception Unhandled' to pause the"
                         " isolate when an unhandled exception occurs.");
       console.printBold("You can make this the default by running with "
                         "--pause-isolates-on-unhandled-exceptions");
     }
   }
 
   void _reportPause(ServiceEvent event) {
-    if (event.kind == ServiceEvent.kPauseStart) {
+    if (event.kind == ServiceEvent.kNone) {
+      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')");
     } else if (event.kind == ServiceEvent.kPauseExit) {
       console.print(
           "Paused at isolate exit "
           "(type 'continue' or [F7] to exit the isolate')");
       _reportIsolateError(isolate, event.kind);
     } else if (event.kind == ServiceEvent.kPauseException) {
       console.print(
@@ skipping 1132 matching lines @@
         }
       });
   }
 
   void focus() {
     $['textBox'].focus();
   }
 
   DebuggerInputElement.created() : super.created();
 }