Fix disable and enable for background app crashes on Windows and Linux

chrome/browser/background_mode_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 "app/l10n_util.h"
 #include "app/resource_bundle.h"
 #include "base/base_paths.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
@@ skipping 298 matching lines @@
     int command_id,
     menus::Accelerator* accelerator) {
   // No accelerators for status icon context menus.
   return false;
 }
 
 void BackgroundModeManager::RemoveStatusTrayIcon() {
   if (status_icon_)
     status_tray_->RemoveStatusIcon(status_icon_);
   status_icon_ = NULL;
+  context_menu_ = NULL;  // Do not delete, points within status_icon_
 }
 
 void BackgroundModeManager::ExecuteApplication(int item) {
   DCHECK(item >= 0 && item < static_cast<int>(applications_.size()));
   Browser* browser = BrowserList::GetLastActive();
   if (!browser) {
     Browser::OpenEmptyWindow(profile_);
     browser = BrowserList::GetLastActive();
   }
   const Extension* extension = applications_.GetExtension(item);
@@ skipping 39 matching lines @@
   // is always running on that platform, making it superfluous.
 #if defined(OS_CHROMEOS)
   return false;
 #else
   bool background_mode_enabled =
       !command_line->HasSwitch(switches::kDisableBackgroundMode) &&
       !command_line->HasSwitch(switches::kDisableExtensions);
   return background_mode_enabled;
 #endif
 }