Redo LocationManager to use HTML5 History API

runtime/bin/vmservice/client/lib/src/elements/code_view.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="nav_bar.html">
 <link rel="import" href="script_ref.html">
 <polymer-element name="code-view" extends="observatory-element">
   <template>
     <link rel="stylesheet" href="css/shared.css">
     <style>
       div.flex-row:hover {
@@ skipping 39 matching lines @@
         margin-left: 10px;
         margin-right: 10px;
       }
 
     </style>
     <nav-bar>
       <top-nav-menu></top-nav-menu>
       <isolate-nav-menu isolate="{{ code.isolate }}"></isolate-nav-menu>
       <nav-menu link="." anchor="{{ code.name }}" last="{{ true }}"></nav-menu>
       <nav-refresh callback="{{ refresh }}"></nav-refresh>
+      <nav-control></nav-control>
     </nav-bar>
     <div class="content">
       <template if="{{ code.isDartCode && code.isOptimized }}">
         <h1>Optimized code for {{ code.name }}</h1>
       </template>
       <template if="{{ !(code.isDartCode && code.isOptimized) }}">
         <h1>Code for {{ code.name }}</h1>
       </template>
       <div class="memberList">
         <div class="memberItem">
@@ skipping 87 matching lines @@
             <div class="flex-item-fixed-6-12 monospace">
               {{ instruction.human }}
             </div>
           </template>
         </div>
       </template>
     </div>
   </template>
   <script type="application/dart" src="code_view.dart"></script>
 </polymer-element>