Store the "browser autorestarted, last session must be restored" information in a preference.

chrome/browser/upgrade_detector.cc

 // Copyright (c) 2011 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/upgrade_detector.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/ui/browser_list.h"
@@ skipping 15 matching lines @@
   // be, we assume it is for testing and switch to using seconds instead of
   // hours.
   const CommandLine& cmd_line = *CommandLine::ForCurrentProcess();
   return !cmd_line.GetSwitchValueASCII(
       switches::kCheckForUpdateIntervalSec).empty();
 }
 
 // static
 void UpgradeDetector::RegisterPrefs(PrefService* prefs) {
   prefs->RegisterBooleanPref(prefs::kRestartLastSessionOnShutdown, false);
+  prefs->RegisterBooleanPref(prefs::kWasRestarted, false);
 }
 
 int UpgradeDetector::GetIconResourceID(UpgradeNotificationIconType type) {
   bool badge = type == UPGRADE_ICON_TYPE_BADGE;
   switch (upgrade_notification_stage_) {
     case UPGRADE_ANNOYANCE_CRITICAL:
       // The critical annoyance state, somewhat ironically, re-purposes the
       // icon for the second highest severity state, since that state has the
       // icon most closely resembling the one requested of this feature and the
       // critical annoyance is never part of the sliding scale of severity
@@ skipping 72 matching lines @@
       break;
     case IDLE_STATE_ACTIVE:
     case IDLE_STATE_UNKNOWN:
       break;
     default:
       NOTREACHED();  // Need to add any new value above (either providing
                      // automatic restart or show notification to user).
       break;
   }
 }