In Chrome ASH on Windows 8 make sure that the browser object is closed before destroying it.

chrome/browser/lifetime/application_lifetime.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/browser_list.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/download/download_service.h"
 #include "chrome/browser/metrics/thread_watcher.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list_impl.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/tab_contents/tab_contents.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/browser_shutdown.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_details.h"
@@ skipping 170 matching lines @@
       if (i != BrowserList::end() && browser == *i) {
         // Destroying the browser should have removed it from the browser list.
         // We should never get here.
         NOTREACHED();
         return;
       }
     }
   }
 }
 
+void CloseAllBrowsersOfType(chrome::HostDesktopType type) {
+  chrome::BrowserListImpl* ash_browser_list =
+      chrome::BrowserListImpl::GetInstance(type);
+  if (ash_browser_list) {
+    for (chrome::BrowserListImpl::const_iterator i = ash_browser_list->begin();
+            i != ash_browser_list->end(); ++i) {
+      Browser* browser = *i;
+      browser->window()->Close();

[sky, 2012/11/29 01:53:27]

What if the close is vetoed for some reason?

[ananta, 2012/11/29 02:39:41]

I added a comment explaining this. The CloseAllBrowsers function above also
suffers from the same limitation, as were the other examples i found in the code
base. A possible option could be to expose the native CloseNow functionality in
the Widget which forcibly deletes the window. 

Did not deem it necessary for this use case as the actual Browser will be
destroyed anyway subsequently.

+    }
+  }
+}
+
 void AttemptUserExit() {
 #if defined(OS_CHROMEOS)
   chromeos::BootTimesLoader::Get()->AddLogoutTimeMarker("LogoutStarted", false);
   // Write /tmp/uptime-logout-started as well.
   const char kLogoutStarted[] = "logout-started";
   chromeos::BootTimesLoader::Get()->RecordCurrentStats(kLogoutStarted);
 
   // Login screen should show up in owner's locale.
   PrefService* state = g_browser_process->local_state();
   if (state) {
@@ skipping 144 matching lines @@
         MessageLoop::current())
       CloseAllBrowsers();
   }
 }
 
 bool WillKeepAlive() {
   return g_keep_alive_count > 0;
 }
 
 }  // namespace browser