Close AppWindow to perform clean shutdown

extensions/shell/browser/shell_native_app_window.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 "extensions/shell/browser/shell_native_app_window.h"
 
 #include "content/public/browser/web_contents.h"
 #include "ui/aura/window.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/point.h"
@@ skipping 62 matching lines @@
 
 void ShellNativeAppWindow::Hide() {
   GetWindow()->Hide();
 }
 
 void ShellNativeAppWindow::ShowInactive() {
   NOTIMPLEMENTED();
 }
 
 void ShellNativeAppWindow::Close() {
-  NOTIMPLEMENTED();
+  app_window_->OnNativeClose();
 }
 
 void ShellNativeAppWindow::Activate() {
   NOTIMPLEMENTED();
 }
 
 void ShellNativeAppWindow::Deactivate() {
   NOTIMPLEMENTED();
 }
 
@@ skipping 151 matching lines @@
 bool ShellNativeAppWindow::CanHaveAlphaEnabled() const {
   NOTIMPLEMENTED();
   return false;
 }
 
 aura::Window* ShellNativeAppWindow::GetWindow() const {
   return app_window_->web_contents()->GetNativeView();
 }
 
 }  // namespace extensions