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 45 matching lines @@
 
 // Initializes the PrefHashStore for the profile preferences file under
 // |profile_path| without actually loading that profile.
 void InitializePrefHashStoreIfRequired(
     const base::FilePath& profile_path);
 
 // Resets the contents of the preference hash store for the profile at
 // |profile_path|.
 void ResetPrefHashStore(const base::FilePath& profile_path);
 
+// Initializes the preferences for the profile at |profile_path| with the
+// preference values in |master_prefs|. Returns true on success.
+bool InitializePrefsFromMasterPrefs(
+    const base::FilePath& profile_path,
+    const base::DictionaryValue& master_prefs);
+
 }  // namespace chrome_prefs
 
 #endif  // CHROME_BROWSER_PREFS_CHROME_PREF_SERVICE_FACTORY_H_