Make the third party wallpaper syncable through different devices.

chrome/browser/chromeos/extensions/wallpaper_api.h

 // Copyright 2013 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_EXTENSIONS_WALLPAPER_API_H_
 #define CHROME_BROWSER_CHROMEOS_EXTENSIONS_WALLPAPER_API_H_
 
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/chromeos/extensions/wallpaper_function_base.h"
 #include "chrome/common/extensions/api/wallpaper.h"
@@ skipping 23 matching lines @@
 
  private:
   void OnWallpaperDecoded(const gfx::ImageSkia& image) override;
 
   // Generates thumbnail of custom wallpaper. A simple STRETCH is used for
   // generating thumbnail.
   void GenerateThumbnail(const base::FilePath& thumbnail_path,
                          scoped_ptr<gfx::ImageSkia> image);
 
   // Thumbnail is ready. Calls api function javascript callback.
-  void ThumbnailGenerated(base::RefCountedBytes* data);
+  void ThumbnailGenerated(base::RefCountedBytes* original_data,
+                          base::RefCountedBytes* thumbnail_data);
 
   // Called by OnURLFetchComplete().
   void OnWallpaperFetched(bool success, const std::string& response);
 
   scoped_ptr<extensions::api::wallpaper::SetWallpaper::Params> params_;
 
   // Unique file name of the custom wallpaper.
   std::string file_name_;
 
   // User id of the user who initiate this API call.
   AccountId account_id_ = EmptyAccountId();
 
   // User id hash of the logged in user.
   std::string user_id_hash_;
 
   // Sequence token associated with wallpaper operations. Shared with
   // WallpaperManager.
   base::SequencedWorkerPool::SequenceToken sequence_token_;
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_WALLPAPER_API_H_