Update "Predict network actions" UI setting.

chrome/browser/net/prediction_options.h

 // Copyright 2014 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_NET_PREDICTION_OPTIONS_H_
 #define CHROME_BROWSER_NET_PREDICTION_OPTIONS_H_
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
@@ skipping 12 matching lines @@
 enum NetworkPredictionOptions {
   NETWORK_PREDICTION_ALWAYS,
   NETWORK_PREDICTION_WIFI_ONLY,
   NETWORK_PREDICTION_NEVER,
   NETWORK_PREDICTION_UNSET,
 };
 
 void RegisterPredictionOptionsProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry);
 
+// Migrate prefs::kNetworkPredictionEnabled user setting (if exists) to
+// prefs::kNetworkPredictionOptions (if does not have user setting).
+void MigrateNetworkPredictionUserPrefs(PrefService* pref_service);
+
 // The following two global functions determine whether predictive network
 // actions are enabled, based on preferences and network type.
 
 // To be executed on the IO thread only.
 bool CanPredictNetworkActionsIO(ProfileIOData* profile_io_data);
 
 // To be executed on the UI thread only.
 bool CanPredictNetworkActionsUI(PrefService* prefs);
 
 }  // namespace chrome_browser_net
 
 #endif  // CHROME_BROWSER_NET_PREDICTION_OPTIONS_H_