Add request tracing to Observatory:

runtime/bin/vmservice/client/lib/src/app/location_manager.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of app;
 
 abstract class LocationManager extends Observable {
   final _initialPath = '/vm';
   ObservatoryApplication _app;
 
@@ skipping 33 matching lines @@
     if (url.startsWith('#')) {
       url = url.substring(1);
     }
     // Fall through handles '#/'
     // Chop off leading '/'.
     if (url.startsWith('/')) {
       url = url.substring(1);
     }
     var args;
     // Parse out arguments.
-    if (url.contains('#')) {
-      var chunks = url.split('#');
+    if (url.contains('---')) {
+      var chunks = url.split('---');
       url = chunks[0];

[Cutch, 2014/07/30 18:47:18]

Does this support multiple arguments?

Could we write a simple unit test to verify that we parse out multiple
arguments?

[turnidge, 2014/07/30 19:28:15]

Yes, it supports multiple arguments.  This is only a separator before the
arguments.

Do we have unit tests for Observatory?  Can I want until Daniel has added his
unit tests he is working on so that I can reuse whatever infrastructure he is
adding?

[Cutch, 2014/07/30 21:58:39]

We don't have unit tests for frontend Observatory. Daniel's work will let us
unit test against libservice. I'm fine punting on this but we'll have to figure
out unittests for frontend Observatory sooner rather than later.

       if ((chunks.length > 1) && (chunks[1] != '')) {
         args = chunks[1];
       }
     }
     _app._visit(url, args);
   }
 
   /// Go back.
   void back() {
     window.history.go(-1);
@@ skipping 57 matching lines @@
     _go(window.location.pathname);
   }
 
   void _onLocationChange(PopStateEvent _) {
     _go(window.location.pathname);
   }
 
   /// Given an application url, generate a link for an anchor tag.
   String makeLink(String url) => url;
 }