Add breadcrumb for the VM.

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

 <link rel="import" href="../../../../packages/polymer/polymer.html">
 <link rel="import" href="class_ref.html">
 <link rel="import" href="curly_block.html">
 <link rel="import" href="eval_box.html">
 <link rel="import" href="field_ref.html">
 <link rel="import" href="function_ref.html">
 <link rel="import" href="instance_ref.html">
 <link rel="import" href="observatory_element.html">
 <link rel="import" href="library_ref.html">
 <link rel="import" href="nav_bar.html">
 <link rel="import" href="script_ref.html">
 <link rel="import" href="view_footer.html">
 
 <polymer-element name="library-view" extends="observatory-element">
   <template>
     <link rel="stylesheet" href="css/shared.css">
 
     <nav-bar>
       <top-nav-menu></top-nav-menu>
+      <vm-nav-menu vm="{{ library.isolate.vm }}"></vm-nav-menu>
       <isolate-nav-menu isolate="{{ library.isolate }}"></isolate-nav-menu>
       <library-nav-menu library="{{ library }}" last="{{ true }}"></library-nav-menu>
       <nav-refresh callback="{{ refreshCoverage }}" label="Refresh Coverage"></nav-refresh>
       <nav-refresh callback="{{ refresh }}"></nav-refresh>
     </nav-bar>
 
     <div class="content">
       <h1>
         <!-- TODO(turnidge): Handle unnamed libraries -->
         library {{ library.name }}
@@ skipping 104 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="library_view.dart"></script>