components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/ui/webui/flags_ui.cc

Index: chrome/browser/ui/webui/flags_ui.cc
diff --git a/chrome/browser/ui/webui/flags_ui.cc b/chrome/browser/ui/webui/flags_ui.cc
index 281e04baefe9b173d0cdd0062ad39bdeef762df5..a530ee45dbec27b10fd42e6c55569929b8b94dab 100644
--- a/chrome/browser/ui/webui/flags_ui.cc
+++ b/chrome/browser/ui/webui/flags_ui.cc
@@ -208,9 +208,9 @@ void FlagsUI::RegisterPrefs(PrefRegistrySimple* registry) {
 
 #if defined(OS_CHROMEOS)
 // static
-void FlagsUI::RegisterUserPrefs(PrefRegistrySyncable* registry) {
+void FlagsUI::RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterListPref(prefs::kEnabledLabsExperiments,
-                             PrefRegistrySyncable::UNSYNCABLE_PREF);
+                             user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 void FlagsUI::FinishInitialization(