Restore to user selected wallpaper after browser crash

ash/shell_delegate.h

 // Copyright (c) 2012 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 ASH_SHELL_DELEGATE_H_
 #define ASH_SHELL_DELEGATE_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 12 matching lines @@
 
 namespace ash {
 
 class AppListViewDelegate;
 class LauncherDelegate;
 class LauncherModel;
 struct LauncherItem;
 class ScreenshotDelegate;
 class SystemTray;
 class SystemTrayDelegate;
+class UserWallpaperDelegate;
 
 // Delegate of the Shell.
 class ASH_EXPORT ShellDelegate {
  public:
   // Source requesting the window list.
   enum CycleSource {
     // Windows are going to be used for alt-tab (or F5).
     SOURCE_KEYBOARD,
 
     // Windows are going to be cycled from the launcher.
@@ skipping 34 matching lines @@
   virtual void StartPartialScreenshot(
       ScreenshotDelegate* screenshot_delegate) = 0;
 
   // Creates a new LauncherDelegate. Shell takes ownership of the returned
   // value.
   virtual LauncherDelegate* CreateLauncherDelegate(
       ash::LauncherModel* model) = 0;
 
   // Creates a system-tray delegate. Shell takes ownership of the delegate.
   virtual SystemTrayDelegate* CreateSystemTrayDelegate(SystemTray* tray) = 0;
+
+  // Creates a user wallpaper delegate. Shell takes ownership of the delegate.
+  virtual UserWallpaperDelegate* CreateUserWallpaperDelegate() = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_DELEGATE_H_