Add "Show saved copy" button in dino page when there's offline copy

components/error_page.gypi

 # Copyright 2014 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': [
     {
       # GN version: //components/error_page/common
       'target_name': 'error_page_common',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../url/url.gyp:url_lib',
         'url_formatter/url_formatter.gyp:url_formatter',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
         'error_page/common/error_page_params.cc',
         'error_page/common/error_page_params.h',
         'error_page/common/net_error_info.cc',
         'error_page/common/net_error_info.h',
+        'error_page/common/offline_page_types.h',
       ],
     },
   ],
   'conditions': [
     ['OS != "ios"', {
       'targets': [
         {
           # GN version: //components/error_page/renderer
           'target_name': 'error_page_renderer',
           'type': 'static_library',
@@ skipping 12 matching lines @@
           ],
           'sources': [
             'error_page/renderer/net_error_helper_core.cc',
             'error_page/renderer/net_error_helper_core.h',
           ],
         }
       ],
     }],
   ],
 }