Asynchronously load wallpapers when user pod is selected.

chrome/browser/chromeos/login/user_manager_impl.cc

Index: chrome/browser/chromeos/login/user_manager_impl.cc
diff --git a/chrome/browser/chromeos/login/user_manager_impl.cc b/chrome/browser/chromeos/login/user_manager_impl.cc
index a004cc9adf88ea1ca21497bc0b12c834f340c121..3cfbb7dab38d3bc6267d7567ca5d6e7a09317c71 100644
--- a/chrome/browser/chromeos/login/user_manager_impl.cc
+++ b/chrome/browser/chromeos/login/user_manager_impl.cc
@@ -448,6 +448,13 @@ void UserManagerImpl::StubUserLoggedIn() {
                             kStubDefaultImageIndex);
 }
 
+void UserManagerImpl::UserSelected(const std::string& email) {
+  if (IsKnownUser(email)) {
+    ash::Shell::GetInstance()->desktop_background_controller()->
+        SetDefaultWallpaper(FindUserWallpaperIndex(email));
+  }
+}
+
 void UserManagerImpl::RemoveUser(const std::string& email,
                                  RemoveUserDelegate* delegate) {
   if (!IsKnownUser(email))
@@ -882,6 +889,20 @@ const User* UserManagerImpl::FindUserInList(const std::string& email) const {
   return NULL;
 }
 
+int UserManagerImpl::FindUserWallpaperIndex(const std::string& email) {
+  PrefService* local_state = g_browser_process->local_state();
+  const DictionaryValue* user_wallpapers =
+      local_state->GetDictionary(UserManager::kUserWallpapers);
+  int index;
+  if (!user_wallpapers->GetIntegerWithoutPathExpansion(email, &index))
+    index = current_user_wallpaper_index_;
+  if (index < 0 || index >= ash::GetWallpaperCount()) {
+      index = ash::GetDefaultWallpaperIndex();
+      SaveUserWallpaperIndex(index);
+  }
+  return index;
+}
+
 void UserManagerImpl::NotifyOnLogin() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   content::NotificationService::current()->Notify(
@@ -944,19 +965,7 @@ int UserManagerImpl::GetUserWallpaperIndex() {
   const chromeos::User& user = GetLoggedInUser();
   std::string username = user.email();
   DCHECK(!username.empty());
-
-  PrefService* local_state = g_browser_process->local_state();
-  const DictionaryValue* user_wallpapers =
-      local_state->GetDictionary(UserManager::kUserWallpapers);
-  int index;
-  if (!user_wallpapers->GetIntegerWithoutPathExpansion(username, &index))
-    index = current_user_wallpaper_index_;
-
-  if (index < 0 || index >= ash::GetWallpaperCount()) {
-    index = ash::GetDefaultWallpaperIndex();
-    SaveUserWallpaperIndex(index);
-  }
-  return index;
+  return FindUserWallpaperIndex(username);
 }
 
 void UserManagerImpl::SaveUserWallpaperIndex(int wallpaper_index) {