Fix some service protocol isolate lifecycle races

runtime/observatory/lib/src/elements/isolate_summary.html

 <link rel="import" href="../../../../packages/polymer/polymer.html">
 <link rel="import" href="action_link.html">
 <link rel="import" href="function_ref.html">
 <link rel="import" href="isolate_ref.html">
 <link rel="import" href="observatory_element.html">
 <link rel="import" href="script_inset.html">
 <link rel="import" href="script_ref.html">
 <polymer-element name="isolate-summary" extends="observatory-element">
   <template>
     <link rel="stylesheet" href="css/shared.css">
@@ skipping 37 matching lines @@
   <template>
     <template if="{{ isolate.pauseEvent != null }}">
       <template if="{{ isolate.pauseEvent.kind == 'PauseStart' }}">
         at isolate start
       </template>
 
       <template if="{{ isolate.pauseEvent.kind == 'PauseExit' }}">
         at isolate exit
       </template>
 
+      <template if="{{ isolate.pauseEvent.kind == 'None' }}">
+        not yet runnable
+      </template>
+
       <template if="{{ isolate.pauseEvent.kind == 'PauseInterrupted' ||
                        isolate.pauseEvent.kind == 'PauseBreakpoint' ||
                        isolate.pauseEvent.kind == 'PauseException' }}">
         <template if="{{ isolate.pauseEvent.breakpoint != null }}">
           by breakpoint
         </template>
         <template if="{{ isolate.pauseEvent.kind == 'PauseException' }}">
           by exception
         </template>
         <template if="{{ isolate.topFrame != null }}">
@@ skipping 152 matching lines @@
     <div class="chart-wrapper" id="isolate-counter-chart">
       <div class="chart-host-wrapper">
         <div class="chart-host" id="isolate-counter-chart-host"></div>
         <div class="chart-legend-host" id="isolate-counter-chart-legend-host"></div>
       </div>
   </div>
   </template>
 </polymer-element>
 
 <script type="application/dart" src="isolate_summary.dart"></script>