Use a #fefefe solid color wallpaper background before user login for GAIA login flow

chrome/browser/ui/webui/options2/chromeos/set_wallpaper_options_handler2.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/set_wallpaper_options_handler2.h"
 
 #include "ash/desktop_background/desktop_background_controller.h"
 #include "ash/shell.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 201 matching lines @@
       !args->GetString(0, &image_url))
     NOTREACHED();
 
   if (image_url.empty())
     return;
 
   int user_image_index;
   if (IsDefaultWallpaperURL(image_url, &user_image_index)) {
     UserManager::Get()->SaveLoggedInUserWallpaperProperties(User::DEFAULT,
                                                             user_image_index);
-    ash::Shell::GetInstance()->user_wallpaper_delegate()->
-        SetLoggedInUserWallpaper();
+    ash::Shell::GetInstance()->user_wallpaper_delegate()->InitializeWallpaper();
   }
 }
 
 void SetWallpaperOptionsHandler::HandleRandomWallpaper(const ListValue* args) {
   int index = ash::GetRandomWallpaperIndex();
   UserManager::Get()->SaveLoggedInUserWallpaperProperties(User::RANDOM, index);
   ash::Shell::GetInstance()->desktop_background_controller()->
       SetDefaultWallpaper(index);
   base::StringValue image_url(GetDefaultWallpaperThumbnailURL(index));
   base::FundamentalValue is_random(true);
   web_ui()->CallJavascriptFunction("SetWallpaperOptions.setSelectedImage",
                                    image_url, is_random);
 }
 
 gfx::NativeWindow SetWallpaperOptionsHandler::GetBrowserWindow() const {
   Browser* browser =
       browser::FindBrowserWithProfile(Profile::FromWebUI(web_ui()));
   if (!browser)
     return NULL;
   return browser->window()->GetNativeHandle();
 }
 
 }  // namespace options2
 }  // namespace chromeos