components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/extensions/test_extension_prefs.h

Index: chrome/browser/extensions/test_extension_prefs.h
diff --git a/chrome/browser/extensions/test_extension_prefs.h b/chrome/browser/extensions/test_extension_prefs.h
index b28aa5ec2a6700549608e25dab09c78ca03ef07d..8bd518c55bbaed6460340bc2916c596ec633dca9 100644
--- a/chrome/browser/extensions/test_extension_prefs.h
+++ b/chrome/browser/extensions/test_extension_prefs.h
@@ -13,7 +13,6 @@
 #include "chrome/common/extensions/manifest.h"
 
 class ExtensionPrefValueMap;
-class PrefRegistrySyncable;
 class PrefService;
 class PrefServiceSyncable;
 
@@ -22,6 +21,10 @@ class DictionaryValue;
 class SequencedTaskRunner;
 }
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 namespace extensions {
 class Extension;
 class ExtensionPrefs;
@@ -38,7 +41,7 @@ class TestExtensionPrefs {
       return *prefs_.get();
   }
   PrefService* pref_service();
-  const scoped_refptr<PrefRegistrySyncable>& pref_registry();
+  const scoped_refptr<user_prefs::PrefRegistrySyncable>& pref_registry();
   void ResetPrefRegistry();
   const base::FilePath& temp_dir() const { return temp_dir_.path(); }
   const base::FilePath& extensions_dir() const { return extensions_dir_; }
@@ -81,7 +84,7 @@ class TestExtensionPrefs {
   base::ScopedTempDir temp_dir_;
   base::FilePath preferences_file_;
   base::FilePath extensions_dir_;
-  scoped_refptr<PrefRegistrySyncable> pref_registry_;
+  scoped_refptr<user_prefs::PrefRegistrySyncable> pref_registry_;
   scoped_ptr<PrefServiceSyncable> pref_service_;
   scoped_ptr<ExtensionPrefs> prefs_;
   scoped_ptr<ExtensionPrefValueMap> extension_pref_value_map_;