chromeos: Migrate SignOut and RequestRestartForUpdate to mojo interface

ash/common/wm_shell.cc

 // Copyright 2016 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 "ash/common/wm_shell.h"
 
 #include <utility>
 
 #include "ash/common/accelerators/accelerator_controller.h"
 #include "ash/common/accelerators/ash_focus_manager_factory.h"
@@ skipping 337 matching lines @@
 void WmShell::SetKeyboardUI(std::unique_ptr<KeyboardUI> keyboard_ui) {
   keyboard_ui_ = std::move(keyboard_ui);
 }
 
 void WmShell::SetSystemTrayDelegate(
     std::unique_ptr<SystemTrayDelegate> delegate) {
   DCHECK(delegate);
   system_tray_delegate_ = std::move(delegate);
   system_tray_delegate_->Initialize();
 #if defined(OS_CHROMEOS)
+  // Accesses WmShell in its constructor.

[James Cook, 2016/11/15 22:43:18]

I left this where it is because WmShell is probably going to go away, or be
folded into ash::Shell, in the next couple months. Initialization of the
LogoutConfirmationController could probably move into WmShell::Initialize() but
destruction looks like it needs to happen before all windows are closed, so I
would have to introduce a DeleteLogoutConfirmationController method.

   logout_confirmation_controller_.reset(new LogoutConfirmationController(
-      base::Bind(&SystemTrayDelegate::SignOut,
-                 base::Unretained(system_tray_delegate_.get()))));
+      base::Bind(&SystemTrayController::SignOut,
+                 base::Unretained(system_tray_controller_.get()))));
 #endif
 }
 
 void WmShell::DeleteSystemTrayDelegate() {
   DCHECK(system_tray_delegate_);
 #if defined(OS_CHROMEOS)
+  // Accesses WmShell in its destructor.
   logout_confirmation_controller_.reset();
 #endif
   system_tray_delegate_.reset();
 }
 
 void WmShell::DeleteWindowCycleController() {
   window_cycle_controller_.reset();
 }
 
 void WmShell::DeleteWindowSelectorController() {
@@ skipping 19 matching lines @@
 void WmShell::DeleteToastManager() {
   toast_manager_.reset();
 }
 
 void WmShell::SetAcceleratorController(
     std::unique_ptr<AcceleratorController> accelerator_controller) {
   accelerator_controller_ = std::move(accelerator_controller);
 }
 
 }  // namespace ash