Fix Observatory code coverage

runtime/bin/vmservice/client/lib/src/app/application.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;
 
 /// A [Pane] controls the user interface of Observatory. At any given time
 /// one pane will be the current pane. Panes are registered at startup.
 /// When the user navigates within the application, each pane is asked if it
 /// can handle the current location, the first pane to say yes, wins.
@@ skipping 108 matching lines @@
   final _paneRegistry = new List<Pane>();
   ServiceObjectPane _serviceObjectPane;
   Pane _currentPane;
   @observable final LocationManager locationManager;
   @observable final VM vm;
   @observable Isolate isolate;
   @reflectable final ObservatoryApplicationElement rootElement;
 
   @reflectable ServiceObject lastErrorOrException;
 
-  /// Any client-level arguments for viewing the current response.
-  @observable String args;
-  // TODO(turnidge): Make args a Map.
-
   void _initOnce() {
     _registerPanes();
     vm.errors.stream.listen(_onError);
     vm.exceptions.stream.listen(_onException);
     location = locationManager;
     locationManager._init(this);
   }
 
   void _registerPanes() {
     if (_serviceObjectPane != null) {
       // Already done.
       return;
     }
     // Register ClassTreePane.
     _paneRegistry.add(new ClassTreePane(this));
     _paneRegistry.add(new ErrorViewPane(this));
     // Note that ServiceObjectPane must be the last entry in the list as it is
     // the catch all.
     _serviceObjectPane = new ServiceObjectPane(this);
     _paneRegistry.add(_serviceObjectPane);
   }
 
   void _onError(ServiceError error) {
     lastErrorOrException = error;
-    _visit('error/');
+    _visit('error/', null);
   }
 
   void _onException(ServiceException exception) {
     lastErrorOrException = exception;
-    _visit('error/');
+    _visit('error/', null);
   }
 
-  void _visit(String url) {
+  void _visit(String url, String args) {
+    // TODO(johnmccutchan): Pass [args] to pane.
     for (var i = 0; i < _paneRegistry.length; i++) {
       var pane = _paneRegistry[i];
       if (pane.canVisit(url)) {
         _installPane(pane);
         pane.visit(url);
         return;
       }
     }
     throw new FallThroughError();
   }
@@ skipping 25 matching lines @@
   }
 
   ObservatoryApplication(this.rootElement) :
       locationManager = new HashLocationManager(),
       vm = new HttpVM() {
     _initOnce();
   }
 }
 
 LocationManager location;