components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/sync/invalidations/invalidator_storage.h

Index: chrome/browser/sync/invalidations/invalidator_storage.h
diff --git a/chrome/browser/sync/invalidations/invalidator_storage.h b/chrome/browser/sync/invalidations/invalidator_storage.h
index dcd3c6e26c7a95752f440c56efebad42adc90174..9db657b2227d0f7d1bb64f3700680353b5e17479 100644
--- a/chrome/browser/sync/invalidations/invalidator_storage.h
+++ b/chrome/browser/sync/invalidations/invalidator_storage.h
@@ -16,13 +16,16 @@
 #include "sync/notifier/invalidation_state_tracker.h"
 
 class PrefService;
-class PrefRegistrySyncable;
 
 namespace base {
 class DictionaryValue;
 class ListValue;
 }
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 namespace browser_sync {
 
 // TODO(tim): Bug 124137. We may want to move this outside of sync/ into a
@@ -33,7 +36,7 @@ namespace browser_sync {
 class InvalidatorStorage : public base::SupportsWeakPtr<InvalidatorStorage>,
                            public syncer::InvalidationStateTracker {
  public:
-  static void RegisterUserPrefs(PrefRegistrySyncable* registry);
+  static void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
   // |pref_service| may be NULL (for unit tests), but in that case no setter
   // methods should be called. Does not own |pref_service|.