Add request tracing to Observatory:

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

Index: runtime/bin/vmservice/client/lib/src/app/location_manager.dart
diff --git a/runtime/bin/vmservice/client/lib/src/app/location_manager.dart b/runtime/bin/vmservice/client/lib/src/app/location_manager.dart
index eb4d89008bbd255987e71dcf69cd2d2be5e46296..04b6d84bbf7f69a13984f2e8497871bd914440dc 100644
--- a/runtime/bin/vmservice/client/lib/src/app/location_manager.dart
+++ b/runtime/bin/vmservice/client/lib/src/app/location_manager.dart
@@ -51,8 +51,8 @@ abstract class LocationManager extends Observable {
     }
     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];