components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/chrome_to_mobile_service.h

Index: chrome/browser/chrome_to_mobile_service.h
diff --git a/chrome/browser/chrome_to_mobile_service.h b/chrome/browser/chrome_to_mobile_service.h
index bc2997151eec7a7b9259228a9c2bee8663f5f155..ce37a3cfdb8246347b667baab16c5a60fc0b12fb 100644
--- a/chrome/browser/chrome_to_mobile_service.h
+++ b/chrome/browser/chrome_to_mobile_service.h
@@ -31,13 +31,16 @@ class OAuth2AccessTokenFetcher;
 class Browser;
 class CloudPrintURL;
 class MockChromeToMobileService;
-class PrefRegistrySyncable;
 class Profile;
 
 namespace net {
 class URLFetcher;
 }
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 // ChromeToMobileService connects to the cloud print service to enumerate
 // compatible mobiles owned by its profile and send URLs and MHTML snapshots.
 class ChromeToMobileService : public ProfileKeyedService,
@@ -98,7 +101,7 @@ class ChromeToMobileService : public ProfileKeyedService,
   static bool UpdateAndGetCommandState(Browser* browser);
 
   // Register the user prefs associated with this service.
-  static void RegisterUserPrefs(PrefRegistrySyncable* registry);
+  static void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
   explicit ChromeToMobileService(Profile* profile);
   virtual ~ChromeToMobileService();