If customization includes default wallpaper, download and apply it.

chrome/browser/ui/ash/chrome_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 CHROME_BROWSER_UI_ASH_CHROME_SHELL_DELEGATE_H_
 #define CHROME_BROWSER_UI_ASH_CHROME_SHELL_DELEGATE_H_
 
 #include <string>
 
 #include "ash/shelf/shelf_item_types.h"
@@ skipping 54 matching lines @@
   virtual ash::AccessibilityDelegate* CreateAccessibilityDelegate() OVERRIDE;
   virtual ash::NewWindowDelegate* CreateNewWindowDelegate() OVERRIDE;
   virtual ash::MediaDelegate* CreateMediaDelegate() OVERRIDE;
   virtual ui::MenuModel* CreateContextMenu(
       aura::Window* root,
       ash::ShelfItemDelegate* item_delegate,
       ash::ShelfItem* item) OVERRIDE;
   virtual ash::WindowTreeHostFactory* CreateWindowTreeHostFactory() OVERRIDE;
   virtual ash::GPUSupport* CreateGPUSupport() OVERRIDE;
   virtual base::string16 GetProductName() const OVERRIDE;
+  virtual bool ShouldUseCustomizedDefaultWallpaper() const OVERRIDE;
+  virtual base::FilePath GetCustomizedWallpaperDefaultRescaledSmallFileName()
+      const OVERRIDE;
+  virtual base::FilePath GetCustomizedWallpaperDefaultRescaledLargeFileName()
+      const OVERRIDE;
 
   // content::NotificationObserver override:
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
  private:
   void PlatformInit();
 
   static ChromeShellDelegate* instance_;
 
   content::NotificationRegistrar registrar_;
 
   ChromeLauncherController* shelf_delegate_;
 
 #if defined(OS_CHROMEOS)
   scoped_ptr<chromeos::DisplayConfigurationObserver>
       display_configuration_observer_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ChromeShellDelegate);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_CHROME_SHELL_DELEGATE_H_