[Mac] Move UI item validation to UserInterfaceItemCommandHandler.

chrome/chrome_browser_ui.gypi

 # Copyright 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.
 
 {
   'variables': {
     # There are two sections of sources:
     # * "Platform"-based sources (OS, toolkit, etc.)
     # * Feature/directory-based sources (e.g., history, printing)
 
@@ skipping 1358 matching lines @@
       'browser/ui/cocoa/apps/app_shim_menu_controller_mac.h',
       'browser/ui/cocoa/apps/app_shim_menu_controller_mac.mm',
       'browser/ui/cocoa/apps/quit_with_apps_controller_mac.cc',
       'browser/ui/cocoa/apps/quit_with_apps_controller_mac.h',
       'browser/ui/cocoa/apps/titlebar_background_view.h',
       'browser/ui/cocoa/apps/titlebar_background_view.mm',
       'browser/ui/cocoa/bookmarks/bookmark_menu_bridge.h',
       'browser/ui/cocoa/bookmarks/bookmark_menu_bridge.mm',
       'browser/ui/cocoa/bookmarks/bookmark_menu_cocoa_controller.h',
       'browser/ui/cocoa/bookmarks/bookmark_menu_cocoa_controller.mm',
+      'browser/ui/cocoa/browser_window_command_handler.h',
+      'browser/ui/cocoa/browser_window_command_handler.mm',
       'browser/ui/cocoa/certificate_viewer_mac.mm',
       'browser/ui/cocoa/chrome_command_dispatcher_delegate.h',
       'browser/ui/cocoa/chrome_command_dispatcher_delegate.mm',
       'browser/ui/cocoa/color_chooser_mac.mm',
       'browser/ui/cocoa/confirm_quit.h',
       'browser/ui/cocoa/confirm_quit_panel_controller.h',
       'browser/ui/cocoa/confirm_quit_panel_controller.mm',
       'browser/ui/cocoa/constrained_window/constrained_window_mac.h',
       'browser/ui/cocoa/constrained_window/constrained_window_mac.mm',
       'browser/ui/cocoa/constrained_window/constrained_window_sheet.h',
@@ skipping 1809 matching lines @@
           ],
           'sources': [
             '<@(chrome_browser_ui_non_mobile_sources)',
             '<@(chrome_browser_ui_omnibox_non_mobile_sources)',
           ],
         }],
       ],
     },
   ],
 }