Speed up custom wallpaper switching time and wallpaper manager code refactor

chrome/browser/ui/webui/options2/chromeos/wallpaper_thumbnail_source.cc

 // 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.
 
 #include "chrome/browser/ui/webui/options2/chromeos/wallpaper_thumbnail_source.h"
 
 #include "ash/desktop_background/desktop_background_resources.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/singleton.h"
 #include "base/string_number_conversions.h"
 #include "base/string_piece.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/synchronization/cancellation_flag.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/threading/worker_pool.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
+#include "chrome/browser/chromeos/login/wallpaper_manager.h"
 #include "chrome/browser/io_thread.h"
 #include "chrome/browser/ui/webui/chrome_url_data_manager.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/browser_thread.h"
 #include "grit/ui_resources.h"
 #include "net/base/mime_util.h"
 #include "ui/base/layout.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/codec/png_codec.h"
 
@@ skipping 16 matching lines @@
     return request_id_;
   }
 
   static void Run(scoped_refptr<ThumbnailEncodingOperation> teo) {
     teo->EncodeThumbnail();
   }
 
   void EncodeThumbnail() {
     if (cancel_flag_.IsSet())
       return;
-    gfx::PNGCodec::EncodeBGRASkBitmap(user_->wallpaper_thumbnail(),
-                                      false, &data_->data());
+    gfx::PNGCodec::EncodeBGRASkBitmap(
+        WallpaperManager::Get()->GetCustomWallpaperThumbnail(user_->email()),
+        false, &data_->data());
   }
 
   void Cancel() {
     cancel_flag_.Set();
   }
 
  private:
   friend class base::RefCountedThreadSafe<
       WallpaperThumbnailSource::ThumbnailEncodingOperation>;
 
@@ skipping 168 matching lines @@
     SendResponse(request_id, NULL);
     return;
   }
   const ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   SendResponse(request_id,
                rb.LoadDataResourceBytes(idr, ui::SCALE_FACTOR_100P));
 }
 
 }  // namespace options2
 }  // namespace chromeos