components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/web_resource/promo_resource_service.cc

Index: chrome/browser/web_resource/promo_resource_service.cc
diff --git a/chrome/browser/web_resource/promo_resource_service.cc b/chrome/browser/web_resource/promo_resource_service.cc
index 037b0074625875908e3a941597ce76bf53d179ac..605c3ac928a067485b60592271478b4e67a045fa 100644
--- a/chrome/browser/web_resource/promo_resource_service.cc
+++ b/chrome/browser/web_resource/promo_resource_service.cc
@@ -68,12 +68,14 @@ void PromoResourceService::RegisterPrefs(PrefRegistrySimple* registry) {
 }
 
 // static
-void PromoResourceService::RegisterUserPrefs(PrefRegistrySyncable* registry) {
+void PromoResourceService::RegisterUserPrefs(
+    user_prefs::PrefRegistrySyncable* registry) {
   // TODO(dbeam): This is registered only for migration; remove in M28
   // when all prefs have been cleared.  http://crbug.com/168887
-  registry->RegisterStringPref(prefs::kNtpPromoResourceCacheUpdate,
-                               "0",
-                               PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterStringPref(
+      prefs::kNtpPromoResourceCacheUpdate,
+      "0",
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   NotificationPromo::RegisterUserPrefs(registry);
 }