[protector] Bump Preferences backup version to 3 to mitigate the startup prefs migration.

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 45 matching lines @@
     std::string value;
     if (!it.value().GetAsString(&value))
       NOTREACHED();
     base::StringAppendF(out, "|%s|%s", it.key().c_str(), value.c_str());
   }
 }
 
 }  // namespace
 
 // static
-const int ProtectedPrefsWatcher::kCurrentVersionNumber = 2;
+const int ProtectedPrefsWatcher::kCurrentVersionNumber = 3;
 
 ProtectedPrefsWatcher::ProtectedPrefsWatcher(Profile* profile)
     : is_backup_valid_(true),
       profile_(profile) {
   // Perform necessary pref migrations before actually starting to observe
   // pref changes, otherwise the migration would affect the backup data as well.
   EnsurePrefsMigration();
   pref_observer_.reset(PrefSetObserver::CreateProtectedPrefSetObserver(
       profile->GetPrefs(), this));
   UpdateCachedPrefs();
@@ skipping 124 matching lines @@
 void ProtectedPrefsWatcher::MigrateOldBackupIfNeeded() {
   PrefService* prefs = profile_->GetPrefs();
 
   int current_version = prefs->GetInteger(kBackupVersion);
   VLOG(1) << "Backup version: " << current_version;
   if (current_version == kCurrentVersionNumber)
     return;
 
   switch (current_version) {
     case 1:
+      // Add pinned tabs.
       prefs->Set(kBackupPinnedTabs, *prefs->GetList(prefs::kPinnedTabs));
       // FALL THROUGH
+
+    case 2:
+      // SessionStartupPref migration.
+      DCHECK(prefs->GetBoolean(prefs::kRestoreOnStartupMigrated));
+      prefs->SetInteger(kBackupRestoreOnStartup,
+                        prefs->GetInteger(prefs::kRestoreOnStartup));
+      prefs->Set(kBackupURLsToRestoreOnStartup,
+                 *prefs->GetList(prefs::kURLsToRestoreOnStartup));
+      // FALL THROUGH
   }
 
   prefs->SetInteger(kBackupVersion, kCurrentVersionNumber);
   UpdateBackupSignature();
 }
 
 bool ProtectedPrefsWatcher::UpdateBackupEntry(const std::string& pref_name) {
   PrefService* prefs = profile_->GetPrefs();
   if (pref_name == ExtensionPrefs::kExtensionsPref) {
     // For changes in extension dictionary, do nothing if the IDs list remained
@@ skipping 108 matching lines @@
         NOTREACHED();
         continue;
       }
       StringAppendStringDictionary(tab, &data);
     }
   }
   return data;
 }
 
 }  // namespace protector