Reland "Implement random wallpaper feature"

chrome/browser/chromeos/login/user_manager.cc

Index: chrome/browser/chromeos/login/user_manager.cc
diff --git a/chrome/browser/chromeos/login/user_manager.cc b/chrome/browser/chromeos/login/user_manager.cc
index cde6c0b5c33dcae50b6eaccf32ab811de2bd982b..af1fac9827ea8e0184f490790d8c9b1599108dfa 100644
--- a/chrome/browser/chromeos/login/user_manager.cc
+++ b/chrome/browser/chromeos/login/user_manager.cc
@@ -14,6 +14,8 @@ namespace chromeos {
 // static
 const char UserManager::kLoggedInUsers[] = "LoggedInUsers";
 const char UserManager::kUserWallpapers[] = "UserWallpapers";
+const char UserManager::kUserWallpapersProperties[] =
+    "UserWallpapersProperties";
 const char UserManager::kUserImages[] = "UserImages";
 const char UserManager::kUserDisplayEmail[] = "UserDisplayEmail";
 const char UserManager::kUserOAuthTokenStatus[] = "OAuthTokenStatus";
@@ -78,6 +80,8 @@ void UserManager::RegisterPrefs(PrefService* local_state) {
   local_state->RegisterListPref(kLoggedInUsers, PrefService::UNSYNCABLE_PREF);
   local_state->RegisterDictionaryPref(kUserWallpapers,
                                       PrefService::UNSYNCABLE_PREF);
+  local_state->RegisterDictionaryPref(kUserWallpapersProperties,
+                                      PrefService::UNSYNCABLE_PREF);
   local_state->RegisterDictionaryPref(kUserImages,
                                       PrefService::UNSYNCABLE_PREF);
   local_state->RegisterDictionaryPref(kUserOAuthTokenStatus,