Speed up custom wallpaper switching time and wallpaper manager code refactor

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.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/chromeos/login/signin_screen_handler.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/command_line.h"
@@ skipping 786 matching lines @@
 #if defined(USE_AURA)
   // Display the shutdown animation before actually requesting shutdown.
   ash::Shell::GetInstance()->power_button_controller()->RequestShutdown();
 #else
   DBusThreadManager::Get()->GetPowerManagerClient()->RequestShutdown();
 #endif
 }
 
 void SigninScreenHandler::HandleUserDeselected(const base::ListValue* args) {
   if (delegate_)
-    delegate_->UserDeselected();
+    delegate_->OnUserDeselected();
 }
 
 void SigninScreenHandler::HandleUserSelected(const base::ListValue* args) {
   if (!delegate_)
     return;
 
   std::string email;
   if (!args->GetString(0, &email)) {
     NOTREACHED();
     return;
   }
 
-  delegate_->UserSelected(email);
+  delegate_->OnUserSelected(email);
 }
 
 void SigninScreenHandler::HandleRemoveUser(const base::ListValue* args) {
   if (!delegate_)
     return;
 
   std::string email;
   if (!args->GetString(0, &email)) {
     NOTREACHED();
     return;
@@ skipping 273 matching lines @@
       !dns_clear_task_running_ &&
       network_state_informer_->is_online()) {
     gaia_silent_load_ = true;
     gaia_silent_load_network_ =
         network_state_informer_->active_network_service_path();
     LoadAuthExtension(true, true, false);
   }
 }
 
 }  // namespace chromeos