Fix crash when user closes window prior to the "Confirm Install" prompt showing

chrome/chrome_tests.gypi

 # 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.
 {
   'variables': {
     'chrome_browser_extensions_test_support_sources': [
       # A list of sources which is shared between different browser tests.
       'browser/apps/app_browsertest_util.cc',
       'browser/apps/app_browsertest_util.h',
       'browser/extensions/browsertest_util.cc',
@@ skipping 358 matching lines @@
       'browser/extensions/extension_bindings_apitest.cc',
       'browser/extensions/extension_context_menu_browsertest.cc',
       'browser/extensions/extension_disabled_ui_browsertest.cc',
       'browser/extensions/extension_dom_clipboard_apitest.cc',
       'browser/extensions/extension_fileapi_apitest.cc',
       'browser/extensions/extension_functional_browsertest.cc',
       'browser/extensions/extension_geolocation_apitest.cc',
       'browser/extensions/extension_get_views_apitest.cc',
       'browser/extensions/extension_icon_source_apitest.cc',
       'browser/extensions/extension_incognito_apitest.cc',
+      'browser/extensions/extension_install_prompt_browsertest.cc',
       'browser/extensions/extension_install_ui_browsertest.cc',
       'browser/extensions/extension_javascript_url_apitest.cc',
       'browser/extensions/extension_loading_browsertest.cc',
       'browser/extensions/extension_messages_apitest.cc',
       'browser/extensions/extension_override_apitest.cc',
       'browser/extensions/extension_resource_request_policy_apitest.cc',
       'browser/extensions/extension_startup_browsertest.cc',
       'browser/extensions/extension_storage_apitest.cc',
       'browser/extensions/extension_storage_monitor_browsertest.cc',
       'browser/extensions/extension_tabs_apitest.cc',
@@ skipping 222 matching lines @@
       'browser/ui/cocoa/passwords/manage_passwords_bubble_browsertest.mm',
       'browser/ui/cocoa/profiles/profile_signin_confirmation_view_controller_browsertest.mm',
       'browser/ui/cocoa/ssl_client_certificate_selector_cocoa_browsertest.mm',
       'browser/ui/cocoa/view_id_util_browsertest.mm',
       'browser/ui/content_settings/content_setting_bubble_model_browsertest.cc',
       'browser/ui/find_bar/find_bar_host_browsertest.cc',
       'browser/ui/fullscreen/fullscreen_controller_browsertest.cc',
       'browser/ui/global_error/global_error_service_browsertest.cc',
       'browser/ui/login/login_prompt_browsertest.cc',
       'browser/ui/location_bar/location_bar_browsertest.cc',
+      'browser/ui/native_window_tracker_browsertest.cc',
       'browser/ui/panels/panel_extension_browsertest.cc',
       'browser/ui/passwords/manage_passwords_test.cc',
       'browser/ui/pdf/pdf_browsertest.cc',
       'browser/ui/prefs/prefs_tab_helper_browsertest.cc',
       'browser/ui/settings_window_manager_browsertest.cc',
       'browser/ui/startup/startup_browser_creator_browsertest.cc',
       'browser/ui/sync/one_click_signin_bubble_links_delegate_browsertest.cc',
       'browser/ui/sync/profile_signin_confirmation_helper_browsertest.cc',
       'browser/ui/tab_modal_confirm_dialog_browsertest.cc',
       'browser/ui/tab_modal_confirm_dialog_browsertest.h',
@@ skipping 2558 matching lines @@
             ['enable_webrtc==1', {
               'dependencies': [
                 '../third_party/libjingle/libjingle.gyp:libjingle_webrtc'
               ]
             }],
           ],
         }]
     }],
   ],  # 'conditions'
 }