Switch to using SourceLocation universally in service protocol.

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

Index: runtime/observatory/lib/src/elements/isolate_summary.html
diff --git a/runtime/observatory/lib/src/elements/isolate_summary.html b/runtime/observatory/lib/src/elements/isolate_summary.html
index 618b42ec59029ff0bfcdea42ed8fac9bc9d5f4ba..2840e2a5979c1d087e0bd242a1b2174163db67a0 100644
--- a/runtime/observatory/lib/src/elements/isolate_summary.html
+++ b/runtime/observatory/lib/src/elements/isolate_summary.html
@@ -83,19 +83,18 @@
           by exception
         </template>
         at
-        <function-ref ref="{{ isolate.topFrame['function'] }}">
+        <function-ref ref="{{ isolate.topFrame.function }}">
         </function-ref>
-        (<script-ref ref="{{ isolate.topFrame['script'] }}"
-                     pos="{{ isolate.topFrame['tokenPos'] }}"></script-ref>)
+        (<source-link location="{{ isolate.topFrame.location }}">
+        </source-link>)
       </template>
     </template>
 
     <template if="{{ isolate.running }}">
       at
-      <function-ref ref="{{ isolate.topFrame['function'] }}">
+      <function-ref ref="{{ isolate.topFrame.function }}">
       </function-ref>
-      (<script-ref ref="{{ isolate.topFrame['script'] }}"
-                   pos="{{ isolate.topFrame['tokenPos'] }}"></script-ref>)
+      (<source-link location="{{ isolate.topFrame.location }}"></source-link>)
     </template>
 
   </template>