components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/profiles/profile.h

Index: chrome/browser/profiles/profile.h
diff --git a/chrome/browser/profiles/profile.h b/chrome/browser/profiles/profile.h
index 25bf840a34513da09fa0d177b2a0bcce82077824..5ba08c567861b17ed215ed94a0eea6321421a555 100644
--- a/chrome/browser/profiles/profile.h
+++ b/chrome/browser/profiles/profile.h
@@ -23,7 +23,6 @@ class ExtensionSpecialStoragePolicy;
 class FaviconService;
 class HostContentSettingsMap;
 class PasswordStore;
-class PrefRegistrySyncable;
 class PromoCounter;
 class ProtocolHandlerRegistry;
 class TestingProfile;
@@ -64,6 +63,10 @@ namespace net {
 class SSLConfigService;
 }
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 class Profile : public content::BrowserContext {
  public:
   // Profile services are accessed with the following parameter. This parameter
@@ -134,7 +137,7 @@ class Profile : public content::BrowserContext {
 
   // Profile prefs are registered as soon as the prefs are loaded for the first
   // time.
-  static void RegisterUserPrefs(PrefRegistrySyncable* registry);
+  static void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
   // Gets task runner for I/O operations associated with |profile|.
   static scoped_refptr<base::SequencedTaskRunner> GetTaskRunnerForProfile(