Add breadcrumb for the VM.

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

 <link rel="import" href="../../../../packages/polymer/polymer.html">
 <link rel="import" href="action_link.html">
 <link rel="import" href="curly_block.html">
 <link rel="import" href="eval_box.html">
 <link rel="import" href="function_ref.html">
 <link rel="import" href="isolate_summary.html">
 <link rel="import" href="library_ref.html">
 <link rel="import" href="nav_bar.html">
 <link rel="import" href="observatory_element.html">
 <link rel="import" href="script_inset.html">
 <link rel="import" href="script_ref.html">
 <link rel="import" href="view_footer.html">
 
 <polymer-element name="isolate-view" extends="observatory-element">
   <template>
     <link rel="stylesheet" href="css/shared.css">
     <style>
       .sourceInset {
         padding-left: 15%;
         padding-right: 15%;
       }
       .miniProfileChart {
         width: 80%;
       }
     </style>
 
     <nav-bar>
       <top-nav-menu></top-nav-menu>
-      <isolate-nav-menu isolate="{{ isolate }}" last="{{ true }}">
-      </isolate-nav-menu>
+      <vm-nav-menu vm="{{ isolate.vm }}"></vm-nav-menu>
+      <isolate-nav-menu isolate="{{ isolate }}" last="{{ true }}"></isolate-nav-menu>
       <nav-refresh callback="{{ refreshCoverage }}" label="Refresh Coverage"></nav-refresh>
       <nav-refresh callback="{{ refresh }}"></nav-refresh>
     </nav-bar>
 
     <div class="content">
       <h1>isolate '{{ isolate.name }}'</h1>
     </div>
 
     <br>
     <div class="flex-row">
@@ skipping 95 matching lines @@
     <hr>
 
     <div class="content">
       <eval-box callback="{{ eval }}"></eval-box>
     </div>
     <view-footer></view-footer>
   </template>
 </polymer-element>
 
 <script type="application/dart" src="isolate_view.dart"></script>