Asynchronously load wallpapers when user pod is selected.

chrome/browser/chromeos/background/ash_user_wallpaper_delegate.h

Index: chrome/browser/chromeos/background/ash_user_wallpaper_delegate.h
diff --git a/chrome/browser/chromeos/background/ash_user_wallpaper_delegate.h b/chrome/browser/chromeos/background/ash_user_wallpaper_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..fb39ac2d52b84e7a9721ac06acd2be0bd0a46b83
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+++ b/chrome/browser/chromeos/background/ash_user_wallpaper_delegate.h
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+// 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_CHROMEOS_BACKGROUND_ASH_USER_WALLPAPER_DELEGATE_H_
+#define CHROME_BROWSER_CHROMEOS_BACKGROUND_ASH_USER_WALLPAPER_DELEGATE_H_
+#pragma once
+
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+
+namespace ash {
+class UserWallpaperDelegate;
+}
+
+namespace chromeos {
+
+ash::UserWallpaperDelegate* CreateUserWallpaperDelegate();
+
+}  // namespace chromeos
+#endif  // CHROME_BROWSER_CHROMEOS_BACKGROUND_ASH_USER_WALLPAPER_DELEGATE_H_