Pass the final URL an app was loaded from to the app in Initialize().

mojo/public/dart/src/application.dart

 // Copyright 2014 The Chromium Authors. 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 application;
 
 class _ApplicationImpl extends application_mojom.Application {
   shell_mojom.ShellProxy shell;
   Application _application;
 
   _ApplicationImpl(
       Application application, core.MojoMessagePipeEndpoint endpoint)
       : _application = application, super(endpoint) {
     super.delegate = this;
   }
 
   _ApplicationImpl.fromHandle(Application application, core.MojoHandle handle)
       : _application = application, super.fromHandle(handle) {
     super.delegate = this;
   }
 
-  void initialize(shell_mojom.ShellProxy shellProxy, List<String> args) {
+  void initialize(shell_mojom.ShellProxy shellProxy, List<String> args, String url) {
     assert(shell == null);
     shell = shellProxy;
     _application.initialize(args);
   }
 
   void acceptConnection(
       String requestorUrl,
       service_provider.ServiceProviderStub services,
       service_provider.ServiceProviderProxy exposedServices) =>
       _application._acceptConnection(requestorUrl, services, exposedServices);
@@ skipping 93 matching lines @@
       String requestorUrl,
       service_provider.ServiceProviderStub services,
       service_provider.ServiceProviderProxy exposedServices) {
     var serviceProvider = new ServiceProvider(services, exposedServices);
     _serviceProviders.add(serviceProvider);
     acceptConnection(requestorUrl, serviceProvider);
   }
 
   void acceptConnection(String requestorUrl, ServiceProvider serviceProvider) {}
 }