First cut at "content handling" support in Mojo.

mojo/shell/view_manager_loader.cc

 // 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.
 
 #include "mojo/shell/view_manager_loader.h"
 
 #include "mojo/public/cpp/application/application_connection.h"
 #include "mojo/public/cpp/application/application_impl.h"
 #include "mojo/services/view_manager/view_manager_init_service_impl.h"
 
 namespace mojo {
 
 using service::ViewManagerInitServiceImpl;
 
 namespace shell {
 
 ViewManagerLoader::ViewManagerLoader() {
 }
 
 ViewManagerLoader::~ViewManagerLoader() {
 }
 
 void ViewManagerLoader::LoadService(
     ServiceManager* manager,
     const GURL& url,
-    ScopedMessagePipeHandle shell_handle) {
+    scoped_refptr<LoadServiceCallbacks> callbacks) {
+  ScopedMessagePipeHandle shell_handle = callbacks->RegisterApplication();
+  if (!shell_handle.is_valid())
+    return;
+
   // TODO(sky): this needs some sort of authentication as well as making sure
   // we only ever have one active at a time.
   scoped_ptr<ApplicationImpl> app(
       new ApplicationImpl(this, shell_handle.Pass()));
   apps_.push_back(app.release());
 }
 
 void ViewManagerLoader::OnServiceError(ServiceManager* manager,
                                        const GURL& url) {
 }
 
 bool ViewManagerLoader::ConfigureIncomingConnection(
     ApplicationConnection* connection)  {
   context_.ConfigureIncomingConnection(connection);
   connection->AddService(this);
   return true;
 }
 
 void ViewManagerLoader::Create(
     ApplicationConnection* connection,
     InterfaceRequest<ViewManagerInitService> request) {
   BindToRequest(new ViewManagerInitServiceImpl(connection, &context_),
                 &request);
 }
 
 }  // namespace shell
 }  // namespace mojo