Fix homepage migration for users who never changed their settings.

chrome/browser/protector/protected_prefs_watcher.cc

 // 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.
 
 #include "chrome/browser/protector/protected_prefs_watcher.h"
 
 #include "base/base64.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/stringprintf.h"
@@ skipping 133 matching lines @@
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   DCHECK(type == chrome::NOTIFICATION_PREF_CHANGED);
   const std::string* pref_name = content::Details<std::string>(details).ptr();
   DCHECK(pref_name && pref_observer_->IsObserved(*pref_name));
   if (UpdateBackupEntry(*pref_name))
     UpdateBackupSignature();
 }
 
 void ProtectedPrefsWatcher::EnsurePrefsMigration() {
-  // Force SessionStartupPref migration, if necessary.
-  SessionStartupPref::GetStartupPref(profile_);
+  SessionStartupPref::MigrateIfNecessary(profile_->GetPrefs());
 }
 
 bool ProtectedPrefsWatcher::UpdateCachedPrefs() {
   // Direct access to the extensions prefs is required becase ExtensionService
   // may not yet have been initialized.
   ExtensionPrefs::ExtensionIdSet extension_ids =
       ExtensionPrefs::GetExtensionsFrom(
           profile_->GetPrefs()->GetDictionary(ExtensionPrefs::kExtensionsPref));
   if (extension_ids == cached_extension_ids_)
     return false;
@@ skipping 166 matching lines @@
         NOTREACHED();
         continue;
       }
       StringAppendStringDictionary(tab, &data);
     }
   }
   return data;
 }
 
 }  // namespace protector