Change AuthenticatingURLLoader to be a URLLoaderInterceptor

shell/application_manager/application_manager.cc

Index: shell/application_manager/application_manager.cc
diff --git a/shell/application_manager/application_manager.cc b/shell/application_manager/application_manager.cc
index fb9d467fbdfb407d2d16a42b4a9f5ded45c3e383..1c57f4aeaad755155574a6aef74b12e5e7978c26 100644
--- a/shell/application_manager/application_manager.cc
+++ b/shell/application_manager/application_manager.cc
@@ -188,9 +188,8 @@ void ApplicationManager::ConnectToApplicationWithParameters(
                      &url_response_disk_cache_);
   }
 
-  if (!url_loader_factory_) {
-    ConnectToService(GURL("mojo:authenticating_url_loader"),
-                     &url_loader_factory_);
+  if (!network_service_) {
+    ConnectToService(GURL("mojo:network_service"), &network_service_);
   }
 
   // NOTE: Attempting to initialize the AuthenticationService while connecting
@@ -203,14 +202,18 @@ void ApplicationManager::ConnectToApplicationWithParameters(
       !EndsWith(resolved_url.path(), "/authentication.mojo", true)) {

[qsr, 2015/06/05 10:54:55]

I think we should now be able to not need mojo:authenticating_url_loader to be
bundle with the shell. You can use the network service without an interceptor,
so we should be able to get this.

[blundell, 2015/06/05 13:24:17]

Done.

     authentication::AuthenticationServicePtr authentication_service;
     ConnectToService(GURL("mojo:authentication"), &authentication_service);
-    url_loader_factory_->SetAuthenticationService(
-        authentication_service.Pass());
+    ConnectToService(GURL("mojo:authenticating_url_loader"),
+                     &url_loader_factory_);
+    mojo::URLLoaderInterceptorFactoryPtr interceptor_factory;
+    url_loader_factory_->CreateURLLoaderInterceptorFactory(
+        GetProxy(&interceptor_factory), authentication_service.Pass());
+    network_service_->RegisterURLLoaderInterceptor(interceptor_factory.Pass());
     initialized_authentication_service_ = true;
   }
 
   new NetworkFetcher(options_.disable_cache, options_.predictable_app_filenames,
                      resolved_url, url_response_disk_cache_.get(),
-                     url_loader_factory_.get(), callback);
+                     network_service_.get(), callback);
 }
 
 bool ApplicationManager::ConnectToRunningApplication(