[Extensions] Make chrome://extensions use developerPrivate for packing crxs

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 2486 matching lines @@
       'browser/ui/extensions/extension_installed_bubble.cc',
       'browser/ui/extensions/extension_installed_bubble.h',
       'browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc',
       'browser/ui/webui/extensions/chromeos/kiosk_apps_handler.h',
       'browser/ui/webui/extensions/extension_basic_info.cc',
       'browser/ui/webui/extensions/extension_basic_info.h',
       'browser/ui/webui/extensions/extension_error_ui_util.cc',
       'browser/ui/webui/extensions/extension_error_ui_util.h',
       'browser/ui/webui/extensions/extension_icon_source.cc',
       'browser/ui/webui/extensions/extension_icon_source.h',
-      'browser/ui/webui/extensions/pack_extension_handler.cc',
-      'browser/ui/webui/extensions/pack_extension_handler.h',
       'browser/ui/webui/voice_search_ui.cc',
       'browser/ui/webui/voice_search_ui.h',
     ],
     'chrome_browser_ui_global_error_sources': [
       'browser/ui/cocoa/global_error_bubble_controller.h',
       'browser/ui/cocoa/global_error_bubble_controller.mm',
       'browser/ui/global_error/global_error.cc',
       'browser/ui/global_error/global_error.h',
       'browser/ui/global_error/global_error_bubble_view_base.h',
       'browser/ui/global_error/global_error_service.cc',
@@ skipping 611 matching lines @@
           ],
           'sources': [
             '<@(chrome_browser_ui_non_mobile_sources)',
             '<@(chrome_browser_ui_omnibox_non_mobile_sources)',
           ],
         }],
       ],
     },
   ],
 }