Add "open as window" menu item to NTP app menu.

chrome/browser/extensions/extension_process_manager.cc

 // Copyright (c) 2010 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/extensions/extension_process_manager.h"
 
 #include "chrome/browser/browser_window.h"
 #include "chrome/browser/browsing_instance.h"
 #if defined(OS_MACOSX)
 #include "chrome/browser/extensions/extension_host_mac.h"
@@ skipping 261 matching lines @@
 }
 
 bool ExtensionProcessManager::HasExtensionHost(ExtensionHost* host) const {
   return all_hosts_.find(host) != all_hosts_.end();
 }
 
 void ExtensionProcessManager::Observe(NotificationType type,
                                       const NotificationSource& source,
                                       const NotificationDetails& details) {
   switch (type.value) {
-    case NotificationType::EXTENSIONS_READY:
+    case NotificationType::EXTENSIONS_READY: {
       CreateBackgroundHosts(this,
           Source<Profile>(source).ptr()->GetExtensionsService()->extensions());
       break;
+    }
 
     case NotificationType::EXTENSION_LOADED: {
       ExtensionsService* service =
           Source<Profile>(source).ptr()->GetExtensionsService();
       if (service->is_ready()) {
         const Extension* extension = Details<const Extension>(details).ptr();
         ::CreateBackgroundHost(this, extension);
       }
       break;
     }
@@ skipping 149 matching lines @@
     NotificationType type,
     const NotificationSource& source,
     const NotificationDetails& details) {
   switch (type.value) {
     case NotificationType::BROWSER_WINDOW_READY: {
       // We want to spawn our background hosts as soon as the user opens an
       // incognito window. Watch for new browsers and create the hosts if
       // it matches our profile.
       Browser* browser = Source<Browser>(source).ptr();
       if (browser->profile() == browsing_instance_->profile()) {
+        // On Chrome OS, a login screen is implemented as a browser.
+        // This browser has no extension service.  In this case,
+        // service will be NULL.
         ExtensionsService* service =
             browsing_instance_->profile()->GetExtensionsService();
         if (service && service->is_ready())
           CreateBackgroundHosts(this, service->extensions());
       }
       break;
     }
     default:
       ExtensionProcessManager::Observe(type, source, details);
       break;
   }
 }