Switch to using SourceLocation universally in service protocol.

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 36 matching lines @@
         <isolate-location isolate="{{ isolate }}"></isolate-location>
       </div>
       <div class="flex-item-10-percent">
       </div>
     </div>
     <br>
 
     <template if="{{ isolate.topFrame != null }}">
       <br>
       <div class="content-centered-big">
-         <script-inset script="{{ isolate.topFrame['script'] }}"
-                       currentPos="{{ isolate.topFrame['tokenPos'] }}"
-                       height="200px">
-         </script-inset>
+        <source-inset location="{{ isolate.topFrame.function.location }}"
+                      currentPos="{{ isolate.topFrame.location.tokenPos }}"
+                      height="200px">
+        </source-inset>
       </div>
     </template>
 
     <div class="flex-row">
       <div class="flex-item-20-percent"></div>
       <div class="flex-item-60-percent"><hr></div>
       <div class="flex-item-20-percent"></div>
     </div>
 
     <br>
@@ skipping 67 matching lines @@
     <hr>
 
     <div class="content">
       <eval-box callback="{{ evaluate }}"></eval-box>
     </div>
     <view-footer></view-footer>
   </template>
 </polymer-element>
 
 <script type="application/dart" src="isolate_view.dart"></script>