components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/search_engines/template_url_prepopulate_data.h

Index: chrome/browser/search_engines/template_url_prepopulate_data.h
diff --git a/chrome/browser/search_engines/template_url_prepopulate_data.h b/chrome/browser/search_engines/template_url_prepopulate_data.h
index fc045b8be181261a9c125986387bc1c333c8a095..6bd7882073ae9078d496d2be91515d0bbd43d096 100644
--- a/chrome/browser/search_engines/template_url_prepopulate_data.h
+++ b/chrome/browser/search_engines/template_url_prepopulate_data.h
@@ -14,10 +14,13 @@
 
 class GURL;
 class PrefService;
-class PrefRegistrySyncable;
 class Profile;
 class TemplateURL;
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 namespace TemplateURLPrepopulateData {
 
 extern const int kMaxPrepopulatedEngineID;
@@ -36,7 +39,7 @@ void InitCountryCode(const std::string& country_code);
 
 #endif
 
-void RegisterUserPrefs(PrefRegistrySyncable* registry);
+void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
 // Returns the current version of the prepopulate data, so callers can know when
 // they need to re-merge. If the prepopulate data comes from the preferences