Allow Observatory to run as a hosted web service

runtime/bin/vmservice/client/lib/src/elements/nav_bar.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.
 
 library nav_bar_element;
 
 import 'dart:html';
 import 'observatory_element.dart';
-import 'package:observatory/app.dart';
 import 'package:observatory/service.dart';
 import 'package:polymer/polymer.dart';
 
 
 @CustomTag('nav-bar')
 class NavBarElement extends ObservatoryElement {
   @published bool pad = true;
 
   NavBarElement.created() : super.created();
 }
@@ skipping 36 matching lines @@
   void refreshDone() {
     active = false;
   }
 }
 
 @CustomTag('nav-control')
 class NavControlElement extends ObservatoryElement {
   NavControlElement.created() : super.created();
 
   void forward(Event e, var detail, Element target) {
-    location.forward();
+    app.locationManager.forward();
   }
 
   void back(Event e, var detail, Element target) {
-    location.back();
+    app.locationManager.back();
   }
 }
 
 @CustomTag('top-nav-menu')
 class TopNavMenuElement extends ObservatoryElement {
   @published bool last = false;
 
   TopNavMenuElement.created() : super.created();
 }
 
@@ skipping 28 matching lines @@
   LibraryNavMenuElement.created() : super.created();
 }
 
 @CustomTag('class-nav-menu')
 class ClassNavMenuElement extends ObservatoryElement {
   @published Class cls;
   @published bool last = false;
 
   ClassNavMenuElement.created() : super.created();
 }