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

chrome/browser/chromeos/login/user_manager_impl.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_CHROMEOS_LOGIN_USER_MANAGER_IMPL_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_IMPL_H_
 #pragma once
 
 #include <string>
 
@@ skipping 29 matching lines @@
                         public content::NotificationObserver {
  public:
   // UserManager implementation:
   virtual ~UserManagerImpl();
 
   virtual const UserList& GetUsers() const OVERRIDE;
   virtual void UserLoggedIn(const std::string& email) OVERRIDE;
   virtual void DemoUserLoggedIn() OVERRIDE;
   virtual void GuestUserLoggedIn() OVERRIDE;
   virtual void EphemeralUserLoggedIn(const std::string& email) OVERRIDE;
-  virtual void SetLoggedInUserWallpaper() OVERRIDE;
+  virtual void InitializeWallpaper() OVERRIDE;
   virtual void UserSelected(const std::string& email) OVERRIDE;
   virtual void SessionStarted() OVERRIDE;
   virtual void RemoveUser(const std::string& email,
                           RemoveUserDelegate* delegate) OVERRIDE;
   virtual void RemoveUserFromList(const std::string& email) OVERRIDE;
   virtual bool IsKnownUser(const std::string& email) const OVERRIDE;
   virtual const User* FindUser(const std::string& email) const OVERRIDE;
   virtual const User& GetLoggedInUser() const OVERRIDE;
   virtual User& GetLoggedInUser() OVERRIDE;
   virtual void SaveUserOAuthStatus(
@@ skipping 291 matching lines @@
 
   // Data URL for |downloaded_profile_image_|.
   std::string downloaded_profile_image_data_url_;
 
   DISALLOW_COPY_AND_ASSIGN(UserManagerImpl);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_IMPL_H_