Save display preference on boot

chrome/browser/ui/ash/chrome_shell_delegate_chromeos.cc

 // 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.
 
 #include "chrome/browser/ui/ash/chrome_shell_delegate.h"
 
 #include "ash/accessibility_delegate.h"
 #include "ash/media_delegate.h"
 #include "ash/wm/mru_window_tracker.h"
 #include "ash/wm/window_util.h"
 #include "base/command_line.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/accessibility/accessibility_events.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
 #include "chrome/browser/chromeos/accessibility/magnification_manager.h"
 #include "chrome/browser/chromeos/background/ash_user_wallpaper_delegate.h"
+#include "chrome/browser/chromeos/display/display_configuration_observer.h"
 #include "chrome/browser/chromeos/display/display_preferences.h"
 #include "chrome/browser/chromeos/extensions/media_player_api.h"
 #include "chrome/browser/chromeos/extensions/media_player_event_router.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/speech/tts_controller.h"
 #include "chrome/browser/ui/ash/caps_lock_delegate_chromeos.h"
 #include "chrome/browser/ui/ash/chrome_new_window_delegate_chromeos.h"
 #include "chrome/browser/ui/ash/session_state_delegate_chromeos.h"
 #include "chrome/browser/ui/ash/system_tray_delegate_chromeos.h"
 #include "chrome/browser/ui/browser.h"
@@ skipping 172 matching lines @@
 
 }  // anonymous namespace
 
 bool ChromeShellDelegate::IsFirstRunAfterBoot() const {
   return CommandLine::ForCurrentProcess()->HasSwitch(
       chromeos::switches::kFirstExecAfterBoot);
 }
 
 void ChromeShellDelegate::PreInit() {
   chromeos::LoadDisplayPreferences(IsFirstRunAfterBoot());
+  display_configuration_observer_.reset(
+      new chromeos::DisplayConfigurationObserver());

[Jun Mukai, 2014/01/13 23:51:15]

I'm not sure why moving display_configuration_observer_ to ShellDelegate. 
What's the point? Could you describe why on the CL description or a comment?

[oshima, 2014/01/13 23:58:19]

This should happen before Shell::Init so that observer can store the initial
state. I updated the description and added comment.

 }
 
 void ChromeShellDelegate::Shutdown() {
   content::RecordAction(content::UserMetricsAction("Shutdown"));
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
       RequestShutdown();
+
+  // Let classes unregister themselves as observers of the ash::Shell singleton
+  // before the shell is destroyed.
+  display_configuration_observer_.reset();
 }
 
 ash::CapsLockDelegate* ChromeShellDelegate::CreateCapsLockDelegate() {
   chromeos::input_method::XKeyboard* xkeyboard =
       chromeos::input_method::InputMethodManager::Get()->GetXKeyboard();
   return new CapsLockDelegate(xkeyboard);
 }
 
 ash::SessionStateDelegate* ChromeShellDelegate::CreateSessionStateDelegate() {
   return new SessionStateDelegateChromeos;
@@ skipping 36 matching lines @@
 }
 
 void ChromeShellDelegate::PlatformInit() {
   registrar_.Add(this,
                  chrome::NOTIFICATION_LOGIN_USER_PROFILE_PREPARED,
                  content::NotificationService::AllSources());
   registrar_.Add(this,
                  chrome::NOTIFICATION_SESSION_STARTED,
                  content::NotificationService::AllSources());
 }