components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/managed_mode/managed_user_service.h

Index: chrome/browser/managed_mode/managed_user_service.h
diff --git a/chrome/browser/managed_mode/managed_user_service.h b/chrome/browser/managed_mode/managed_user_service.h
index 7d862e8e4a7a9e90ab85650d8f11e2293125d52c..0b8a5ff1959452fa1377b6c26da194d0f58ef22b 100644
--- a/chrome/browser/managed_mode/managed_user_service.h
+++ b/chrome/browser/managed_mode/managed_user_service.h
@@ -21,9 +21,12 @@
 class Browser;
 class ManagedModeURLFilter;
 class ManagedModeSiteList;
-class PrefRegistrySyncable;
 class Profile;
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 // This class handles all the information related to a given managed profile
 // (e.g. the installed content packs, the default URL filtering behavior, or
 // manual whitelist/blacklist overrides).
@@ -47,7 +50,7 @@ class ManagedUserService : public ProfileKeyedService,
   // Returns the elevation state for specific WebContents.
   bool IsElevatedForWebContents(const content::WebContents* web_contents) const;
 
-  static void RegisterUserPrefs(PrefRegistrySyncable* registry);
+  static void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
   // Returns the URL filter for the IO thread, for filtering network requests
   // (in ManagedModeResourceThrottle).