Nicely handle OnBeforeUnloads with guest and lock mode.

chrome/browser/profiles/profile_window.cc

 // Copyright 2013 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/profiles/profile_window.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 241 matching lines @@
           placeholder_avatar_index)),
       base::Bind(&OpenBrowserWindowForProfile,
                  callback,
                  true,
                  true,
                  desktop_type),
       std::string());
   ProfileMetrics::LogProfileAddNewUser(metric);
 }
 
+void GuestBrowserCloseSuccess(const base::FilePath& profile_path) {
+  chrome::ShowUserManager(profile_path);
+}
+
 void CloseGuestProfileWindows() {
   ProfileManager* profile_manager = g_browser_process->profile_manager();
   Profile* profile = profile_manager->GetProfileByPath(
       ProfileManager::GetGuestProfilePath());
 
   if (profile) {
-    BrowserList::CloseAllBrowsersWithProfile(profile);
+    BrowserList::CloseAllBrowsersWithProfile(
+        profile,
+        base::Bind(&GuestBrowserCloseSuccess));
   }
 }
 
+void LockBrowserCloseSuccess(const base::FilePath& profile_path) {
+  ProfileInfoCache* cache =
+      &g_browser_process->profile_manager()->GetProfileInfoCache();
+
+  cache->SetProfileSigninRequiredAtIndex(
+      cache->GetIndexOfProfileWithPath(profile_path),
+      true);
+  chrome::ShowUserManager(profile_path);
+}
+
 void LockProfile(Profile* profile) {
   DCHECK(profile);
-  ProfileInfoCache& cache =
-      g_browser_process->profile_manager()->GetProfileInfoCache();
-
-  size_t index = cache.GetIndexOfProfileWithPath(profile->GetPath());
-  cache.SetProfileSigninRequiredAtIndex(index, true);
-  chrome::ShowUserManager(profile->GetPath());
-  BrowserList::CloseAllBrowsersWithProfile(profile);
+  if (profile) {
+    BrowserList::CloseAllBrowsersWithProfile(profile,
+        base::Bind(&LockBrowserCloseSuccess));
+  }
 }
 
 void CreateGuestProfileForUserManager(
     const base::FilePath& profile_path_to_focus,
     profiles::UserManagerTutorialMode tutorial_mode,
     const base::Callback<void(Profile*, const std::string&)>& callback) {
   // Create the guest profile, if necessary, and open the User Manager
   // from the guest profile.
   g_browser_process->profile_manager()->CreateProfileAsync(
       ProfileManager::GetGuestProfilePath(),
@@ skipping 84 matching lines @@
     case BrowserWindow::AVATAR_BUBBLE_MODE_SHOW_ERROR:
       *bubble_view_mode = BUBBLE_VIEW_MODE_PROFILE_CHOOSER;
       *tutorial_mode = TUTORIAL_MODE_SHOW_ERROR;
       return;
     default:
       *bubble_view_mode = profiles::BUBBLE_VIEW_MODE_PROFILE_CHOOSER;
   }
 }
 
 }  // namespace profiles