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

components/filesystem/file_system_app.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 "components/filesystem/file_system_app.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "mojo/shell/public/cpp/application_connection.h"
-#include "mojo/shell/public/cpp/application_impl.h"
+#include "mojo/shell/public/cpp/shell.h"
 
 namespace filesystem {
 
-FileSystemApp::FileSystemApp() : app_(nullptr), in_shutdown_(false) {}
+FileSystemApp::FileSystemApp() : shell_(nullptr), in_shutdown_(false) {}
 
 FileSystemApp::~FileSystemApp() {}
 
-void FileSystemApp::Initialize(mojo::ApplicationImpl* app) {
-  app_ = app;
-  tracing_.Initialize(app);
+void FileSystemApp::Initialize(mojo::Shell* shell, const std::string& url,
+                               uint32_t id) {
+  shell_ = shell;
+  tracing_.Initialize(shell, url);
 }
 
 bool FileSystemApp::AcceptConnection(
     mojo::ApplicationConnection* connection) {
   connection->AddService<FileSystem>(this);
   return true;
 }
 
 void FileSystemApp::RegisterDirectoryToClient(DirectoryImpl* directory,
                                               FileSystemClientPtr client) {
@@ skipping 30 matching lines @@
 
 void FileSystemApp::OnDirectoryConnectionError(DirectoryImpl* directory) {
   for (std::vector<Client>::iterator it = client_mapping_.begin();
        it != client_mapping_.end(); ++it) {
     if (it->directory_ == directory) {
       client_mapping_.erase(it);
 
       if (in_shutdown_ && client_mapping_.empty()) {
         // We just cleared the last directory after our shell connection went
         // away. Time to shut ourselves down.
-        app_->Quit();
+        shell_->Quit();
       }
 
       return;
     }
   }
 }
 
 FileSystemApp::Client::Client(DirectoryImpl* directory,
                               FileSystemClientPtr fs_client)
     : directory_(directory), fs_client_(std::move(fs_client)) {}
 
 FileSystemApp::Client::Client(Client&& rhs)
     : directory_(rhs.directory_), fs_client_(std::move(rhs.fs_client_)) {}
 
 FileSystemApp::Client::~Client() {}
 
 FileSystemApp::Client& FileSystemApp::Client::operator=(
     FileSystemApp::Client&& rhs) {
   directory_ = rhs.directory_;
   fs_client_ = std::move(rhs.fs_client_);
   return *this;
 }
 
 }  // namespace filesystem