Fix some Observatory issues that crept in with my last couple changes.

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">
@@ skipping 85 matching lines @@
             <div class="memberItem">
               <template if="{{ isolate.entry != null }}">
                 <div class="memberName">entry</div>
                 <div class="memberValue">
                   <function-ref ref="{{ isolate.entry }}"></function-ref>
                 </div>
               </template>
             </div>
             <div class="memberItem">
               <div class="memberName">isolate id</div>
-              <div class="memberValue">{{ isolate.mainPort }}</div>
+              <div class="memberValue">{{ isolate.number }}</div>
             </div>
           </div>
         </div>
       </div>
     </div>
 
     <hr>
 
     <div class="content">
       libraries ({{ isolate.libraries.length }})
@@ skipping 20 matching lines @@
 
     <div class="content">
       <eval-box callback="{{ eval }}"></eval-box>
     </div>
     <br><br><br><br>
     <br><br><br><br>
   </template>
 </polymer-element>
 
 <script type="application/dart" src="isolate_view.dart"></script>