components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/content_settings/content_settings_pref_provider.h

Index: chrome/browser/content_settings/content_settings_pref_provider.h
diff --git a/chrome/browser/content_settings/content_settings_pref_provider.h b/chrome/browser/content_settings/content_settings_pref_provider.h
index 33f41374ed1e62b0114057fb4f6d1d24bb8749ee..edecd92b2140bf7c37186aa73676bfcd8708d684 100644
--- a/chrome/browser/content_settings/content_settings_pref_provider.h
+++ b/chrome/browser/content_settings/content_settings_pref_provider.h
@@ -17,19 +17,22 @@
 #include "chrome/browser/content_settings/content_settings_utils.h"
 
 class PrefService;
-class PrefRegistrySyncable;
 
 namespace base {
 class DictionaryValue;
 }
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 namespace content_settings {
 
 // Content settings provider that provides content settings from the user
 // preference.
 class PrefProvider : public ObservableProvider {
  public:
-  static void RegisterUserPrefs(PrefRegistrySyncable* registry);
+  static void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
   PrefProvider(PrefService* prefs, bool incognito);
   virtual ~PrefProvider();