components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/chromeos/preferences_unittest.cc

Index: chrome/browser/chromeos/preferences_unittest.cc
diff --git a/chrome/browser/chromeos/preferences_unittest.cc b/chrome/browser/chromeos/preferences_unittest.cc
index 9bc6077a23a3f9a7a88174613d8c9897ffd6fa56..a60a7c2cc91763c752e767e6f96fea638c59efd8 100644
--- a/chrome/browser/chromeos/preferences_unittest.cc
+++ b/chrome/browser/chromeos/preferences_unittest.cc
@@ -62,9 +62,10 @@ TEST(PreferencesTest, TestUpdatePrefOnBrowserScreenDetails) {
   ChromeDownloadManagerDelegate::RegisterUserPrefs(prefs.registry());
   // kSelectFileLastDirectory is registered for Profile. Here we register it for
   // testing.
-  prefs.registry()->RegisterStringPref(prefs::kSelectFileLastDirectory,
-                                       std::string(),
-                                       PrefRegistrySyncable::UNSYNCABLE_PREF);
+  prefs.registry()->RegisterStringPref(
+      prefs::kSelectFileLastDirectory,
+      std::string(),
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 
   StringPrefMember previous;
   previous.Init(prefs::kLanguagePreviousInputMethod, &prefs);