cros: Move wallpaper after login screen is gone

chrome/browser/chromeos/login/ui/login_display_host.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_UI_LOGIN_DISPLAY_HOST_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_UI_LOGIN_DISPLAY_HOST_H_
 
 #include <string>
 
-#include "base/callback.h"
-#include "base/callback_list.h"
+#include "base/callback_forward.h"
 #include "chrome/browser/chromeos/customization/customization_document.h"
 #include "chrome/browser/chromeos/login/oobe_screen.h"
 #include "chrome/browser/chromeos/login/ui/login_display.h"
 #include "ui/gfx/native_widget_types.h"
 
 class AccountId;
 
 namespace chromeos {
 
 class AppLaunchController;
@@ skipping 22 matching lines @@
 
   // Returns instance of the OOBE WebUI.
   virtual OobeUI* GetOobeUI() const = 0;
 
   // Returns the current login view.
   virtual WebUILoginView* GetWebUILoginView() const = 0;
 
   // Called when browsing session starts before creating initial browser.
   virtual void BeforeSessionStart() = 0;
 
-  // Called when user enters or returns to browsing session so
-  // LoginDisplayHost instance may delete itself.
-  virtual void Finalize() = 0;
+  // Called when user enters or returns to browsing session so LoginDisplayHost
+  // instance may delete itself. |completion_callback| will be invoked when the
+  // instance is gone.
+  virtual void Finalize(base::OnceClosure completion_callback) = 0;
 
   // Open proxy settings dialog.
   virtual void OpenProxySettings() = 0;
 
   // Toggles status area visibility.
   virtual void SetStatusAreaVisible(bool visible) = 0;
 
   // Starts out-of-box-experience flow or shows other screen handled by
   // Wizard controller i.e. camera, recovery.
   // One could specify start screen with |first_screen|.
   virtual void StartWizard(OobeScreen first_screen) = 0;
 
   // Returns current WizardController, if it exists.
   // Result should not be stored.
   virtual WizardController* GetWizardController() = 0;
 
   // Returns current AppLaunchController, if it exists.
   // Result should not be stored.
   virtual AppLaunchController* GetAppLaunchController() = 0;
 
   // Starts screen for adding user into session.
-  // |completion_callback| called before display host shutdown.
+  // |completion_callback| is invoked after login display host shutdown.
   // |completion_callback| can be null.
-  virtual void StartUserAdding(const base::Closure& completion_callback) = 0;
+  virtual void StartUserAdding(base::OnceClosure completion_callback) = 0;
 
   // Cancel addint user into session.
   virtual void CancelUserAdding() = 0;
 
   // Starts sign in screen.
   virtual void StartSignInScreen(const LoginScreenContext& context) = 0;
 
   // Invoked when system preferences that affect the signin screen have changed.
   virtual void OnPreferencesChanged() = 0;
 
@@ skipping 13 matching lines @@
   virtual void StartArcKiosk(const AccountId& account_id) = 0;
 
  protected:
   // Default LoginDisplayHost. Child class sets the reference.
   static LoginDisplayHost* default_host_;
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_UI_LOGIN_DISPLAY_HOST_H_