Enable user change background image in settings page in Aura build.

chrome/browser/chromeos/options2/desktop_background_observer.cc

Index: chrome/browser/chromeos/options2/desktop_background_observer.cc
diff --git a/chrome/browser/chromeos/options2/desktop_background_observer.cc b/chrome/browser/chromeos/options2/desktop_background_observer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..07efd874c9de5fd6eff943c69f3495531bb7ddde
--- /dev/null
+++ b/chrome/browser/chromeos/options2/desktop_background_observer.cc
@@ -0,0 +1,57 @@
+// 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/chromeos/options2/desktop_background_observer.h"
+
+#include "ash/shell.h"
+#include "ash/desktop_background/desktop_background_controller.h"
+#include "base/logging.h"
+#include "chrome/browser/chromeos/login/user_manager.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "content/public/browser/notification_service.h"
+
+namespace chromeos {
+
+DesktopBackgroundObserver::DesktopBackgroundObserver() {
+#if defined(USE_AURA)
+  registrar_.Add(
+      this,
+      chrome::NOTIFICATION_DESKTOP_BACKGROUND_CHANGED,
+      content::NotificationService::AllSources());
+#endif
+#if defined(OS_CHROMEOS)
+  registrar_.Add(
+      this,
+      chrome::NOTIFICATION_SESSION_STARTED,
+      content::NotificationService::AllSources());
+#endif
+}
+
+DesktopBackgroundObserver::~DesktopBackgroundObserver() {
+}
+
+void DesktopBackgroundObserver::Observe(int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  switch (type) {
+    case chrome::NOTIFICATION_DESKTOP_BACKGROUND_CHANGED: {
+      int index = *content::Details<int>(details).ptr();
+      ash::Shell::GetInstance()->desktop_background_controller()
+          ->OnDesktopBackgroundChange(index);
+      break;
+    }
+    case chrome::NOTIFICATION_SESSION_STARTED: {
+      chromeos::UserManager* user_manager = chromeos::UserManager::Get();
+      const chromeos::User& user = user_manager->logged_in_user();
+      int index = user_manager->GetUserWallpaper(user.email());
+      ash::Shell::GetInstance()->desktop_background_controller()
+          ->OnDesktopBackgroundChange(index);
+      break;
+    }
+    default:
+      NOTREACHED() << "Unexpected notification " << type;

[flackr, 2012/03/05 16:16:03]

Remove text message, reason for hitting the NOTREACHED is obvious from code and
static text messages increase our binary size.

[bshe, 2012/03/06 01:33:27]

Done.

+  }
+}
+
+}  // namespace chromeos