Extract shell methods from ApplicationImpl into a base class, and pass this to Initialize() instead.

mandoline/services/updater/updater_impl.cc

 // Copyright 2015 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 "mandoline/services/updater/updater_impl.h"
 
 #include <utility>
 
 #include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "mandoline/services/updater/updater_app.h"
 #include "mojo/shell/public/cpp/application_impl.h"
 #include "url/gurl.h"
 
 namespace updater {
 
-UpdaterImpl::UpdaterImpl(mojo::ApplicationImpl* app_impl,
-                         UpdaterApp* application,
+UpdaterImpl::UpdaterImpl(UpdaterApp* application,
                          mojo::InterfaceRequest<Updater> request)
     : application_(application),
-      app_impl_(app_impl),
       binding_(this, std::move(request)) {}
 
 UpdaterImpl::~UpdaterImpl() {
 }
 
 void UpdaterImpl::GetPathForApp(
     const mojo::String& url,
     const Updater::GetPathForAppCallback& callback) {
   // TODO(scottmg): For now, just stub to local files. This will become an
   // integration with components/update_client.
   base::FilePath shell_dir;
   PathService::Get(base::DIR_MODULE, &shell_dir);
   const GURL as_url(url.get());
   const base::FilePath path = shell_dir.Append(base::FilePath::FromUTF8Unsafe(
       as_url.path().substr(2, as_url.path().size() - 3) + ".mojo"));
   callback.Run(path.AsUTF8Unsafe());
 }
 
 }  // namespace updater