Do not migrate NetworkPrediction preference on Android.

chrome/browser/prefs/browser_prefs.cc

 // Copyright 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.
 
 #include "chrome/browser/prefs/browser_prefs.h"
 
 #include <string>
 
 #include "base/debug/trace_event.h"
 #include "base/prefs/pref_registry_simple.h"
@@ skipping 510 matching lines @@
 void MigrateUserPrefs(Profile* profile) {
   PrefService* prefs = profile->GetPrefs();
 
   // Cleanup prefs from now-removed protector feature.
   prefs->ClearPref(kBackupPref);
 
 #if !defined(OS_ANDROID)
   // Cleanup now-removed sync promo error message preference.
   // TODO(fdoray): Remove this when it's safe to do so (crbug.com/268442).
   prefs->ClearPref(kSyncPromoErrorMessage);
+  // Migrate kNetworkPredictionEnabled to kNetworkPredictionOptions when not on
+  // Android.  On Android, platform-specific code performs preference migration.
+  // TODO(bnc): https://crbug.com/401970  Remove migration code after some time.

[Bernhard Bauer, 2014/08/11 09:01:33]

Nit: Instead of "after some time", could you define an objective criterion here?
That way, even if you and me forget about this, someone else who comes across
this code can do the cleanup. 

[Bence, 2014/08/11 13:39:45]

Done.

+  chrome_browser_net::MigrateNetworkPredictionUserPrefs(prefs);
 #endif
 
   PromoResourceService::MigrateUserPrefs(prefs);
   translate::TranslatePrefs::MigrateUserPrefs(prefs, prefs::kAcceptLanguages);
-  chrome_browser_net::MigrateNetworkPredictionUserPrefs(prefs);
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
   autofill::AutofillManager::MigrateUserPrefs(prefs);
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 }
 
 void MigrateBrowserPrefs(Profile* profile, PrefService* local_state) {
   // Copy pref values which have been migrated to user_prefs from local_state,
   // or remove them from local_state outright, if copying is not required.
   int current_version =
@@ skipping 60 matching lines @@
 #if defined(OS_CHROMEOS)
   chromeos::default_pinned_apps_field_trial::MigratePrefs(local_state);
 #endif
 
 #if defined(TOOLKIT_VIEWS)
   MigrateBrowserTabStripPrefs(local_state);
 #endif
 }
 
 }  // namespace chrome