Profile unlock should always use session restore, regardless of system preference.

chrome/browser/ui/startup/startup_browser_creator.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/ui/startup/startup_browser_creator.h"
 
 #include <algorithm>   // For max().
 #include <set>
 
 #include "apps/app_load_service.h"
@@ skipping 370 matching lines @@
 
   // The switches::kRestoreLastSession command line switch is used to restore
   // sessions after a browser self restart (e.g. after a Chrome upgrade).
   // However, new profiles can be created from a browser process that has this
   // switch so do not set the session pref to SessionStartupPref::LAST for
   // those as there is nothing to restore.
   if ((command_line.HasSwitch(switches::kRestoreLastSession) || did_restart) &&
       !profile->IsNewProfile()) {
     pref.type = SessionStartupPref::LAST;
   }
+
+  // A browser starting for a profile being unlocked should always restore.
+  if (!profile->IsGuestSession()) {
+    ProfileInfoCache& info_cache =
+        g_browser_process->profile_manager()->GetProfileInfoCache();
+    size_t index = info_cache.GetIndexOfProfileWithPath(profile->GetPath());
+
+    // If called during CreatePrimaryProfile on startup, |profile| has not yet

[msw, 2014/10/30 22:29:49]

nit: not sure the comment is entirely necessary.

+    // been added to the ProfileInfoCache; other code checks IsSigninRequired
+    // and launches the UserManager if set. Thus here, only handle Profiles
+    // that are in the ProfileInfoCache and have the bit set.
+    if (index != std::string::npos &&
+        info_cache.ProfileIsSigninRequiredAtIndex(index)) {
+        pref.type = SessionStartupPref::LAST;

[msw, 2014/10/30 22:29:50]

nit: fix indent

+    }
+  }
+
   if (pref.type == SessionStartupPref::LAST &&
       IncognitoModePrefs::ShouldLaunchIncognito(command_line, prefs)) {
     // We don't store session information when incognito. If the user has
     // chosen to restore last session and launched incognito, fallback to
     // default launch behavior.
     pref.type = SessionStartupPref::DEFAULT;
   }
 
   return pref;
 }
@@ skipping 345 matching lines @@
   // If we are showing the app list then chrome isn't shown so load the app
   // list's profile rather than chrome's.
   if (command_line.HasSwitch(switches::kShowAppList)) {
     return AppListService::Get(chrome::HOST_DESKTOP_TYPE_NATIVE)->
         GetProfilePath(user_data_dir);
   }
 
   return g_browser_process->profile_manager()->GetLastUsedProfileDir(
       user_data_dir);
 }