[Mac] Add a confirm to quit experiment to about:flags.

chrome/chrome_browser.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': '<(library)',
       'msvs_guid': '5BF908A7-68FB-4A4B-99E3-8C749F1FE4EA',
@@ skipping 884 matching lines @@
         'browser/cocoa/chrome_event_processing_window.h',
         'browser/cocoa/chrome_event_processing_window.mm',
         'browser/cocoa/clear_browsing_data_controller.h',
         'browser/cocoa/clear_browsing_data_controller.mm',
         'browser/cocoa/clickhold_button_cell.h',
         'browser/cocoa/clickhold_button_cell.mm',
         'browser/cocoa/collected_cookies_mac.h',
         'browser/cocoa/collected_cookies_mac.mm',
         'browser/cocoa/command_observer_bridge.h',
         'browser/cocoa/command_observer_bridge.mm',
+        'browser/cocoa/confirm_quit_panel_controller.h',
+        'browser/cocoa/confirm_quit_panel_controller.mm',
         'browser/cocoa/constrained_html_delegate_mac.mm',
         'browser/cocoa/constrained_window_mac.h',
         'browser/cocoa/constrained_window_mac.mm',
         'browser/cocoa/content_exceptions_window_controller.h',
         'browser/cocoa/content_exceptions_window_controller.mm',
         'browser/cocoa/content_setting_bubble_cocoa.h',
         'browser/cocoa/content_setting_bubble_cocoa.mm',
         'browser/cocoa/content_settings_dialog_controller.h',
         'browser/cocoa/content_settings_dialog_controller.mm',
         'browser/cocoa/cookie_details.h',
@@ skipping 2690 matching lines @@
                   'app/nibs/AutoFillDialog.xib',
                   'app/nibs/BookmarkAllTabs.xib',
                   'app/nibs/BookmarkBar.xib',
                   'app/nibs/BookmarkBubble.xib',
                   'app/nibs/BookmarkEditor.xib',
                   'app/nibs/BookmarkNameFolder.xib',
                   'app/nibs/ClearBrowsingData.xib',
                   'app/nibs/CollectedCookies.xib',
                   'app/nibs/Cookies.xib',
                   'app/nibs/CookieDetailsView.xib',
+                  'app/nibs/ConfirmQuitPanel.xib',
                   'app/nibs/ContentBlockedCookies.xib',
                   'app/nibs/ContentBlockedImages.xib',
                   'app/nibs/ContentBlockedJavaScript.xib',
                   'app/nibs/ContentBlockedPlugins.xib',
                   'app/nibs/ContentBlockedPopups.xib',
                   'app/nibs/ContentBubbleGeolocation.xib',
                   'app/nibs/ContentExceptionsWindow.xib',
                   'app/nibs/ContentSettings.xib',
                   'app/nibs/DownloadItem.xib',
                   'app/nibs/DownloadShelf.xib',
@@ skipping 669 matching lines @@
       ],
     },
   ],
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: