Let chrome_prefs handle Preferences initialization from master_preferences.

chrome/browser/prefs/chrome_pref_service_factory.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_PREFS_CHROME_PREF_SERVICE_FACTORY_H_
 #define CHROME_BROWSER_PREFS_CHROME_PREF_SERVICE_FACTORY_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 
 namespace base {
+class DictionaryValue;
 class FilePath;
 class SequencedTaskRunner;
 }
 
 namespace policy {
 class PolicyService;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
@@ skipping 33 matching lines @@
 scoped_ptr<PrefServiceSyncable> CreateProfilePrefs(
     const base::FilePath& pref_filename,
     base::SequencedTaskRunner* pref_io_task_runner,
     policy::PolicyService* policy_service,
     ManagedUserSettingsService* managed_user_settings,
     scoped_ptr<PrefHashStore> pref_hash_store,
     const scoped_refptr<PrefStore>& extension_prefs,
     const scoped_refptr<user_prefs::PrefRegistrySyncable>& pref_registry,
     bool async);
 
-// Initializes a preference hash store for the profile preferences file at
+// Initializes the |pref_hash_store| for the profile preferences file at
 // |pref_filename| without actually loading the profile.
-void InitializeHashStoreForPrefFile(
+void InitializeHashStoreFromPrefFile(
     const base::FilePath& pref_filename,
     base::SequencedTaskRunner* pref_io_task_runner,
     scoped_ptr<PrefHashStore> pref_hash_store);
 
+// Initializes the |pref_hash_store| via the preference values present in
+// |master_prefs|.
+void InitializeHashStoreFromMasterPrefs(
+    const base::DictionaryValue& master_prefs,
+    scoped_ptr<PrefHashStore> pref_hash_store);
+
 }  // namespace chrome_prefs
 
 #endif  // CHROME_BROWSER_PREFS_CHROME_PREF_SERVICE_FACTORY_H_