Inject JSON parsing in WebResource as a callback rather than inheritance

chrome/chrome_browser.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': {
     # All .cc, .h, .m, and .mm files under browser except for:
     # * tests and mocks.
     # * code below browser/chromeos
     # * code below browser/extensions
@@ skipping 3043 matching lines @@
       'browser/themes/theme_service_factory.h',
       'browser/themes/theme_service_mac.mm',
       'browser/themes/theme_syncable_service.cc',
       'browser/themes/theme_syncable_service.h',
     ],
     'chrome_browser_undo_sources': [
       'browser/undo/bookmark_undo_service_factory.cc',
       'browser/undo/bookmark_undo_service_factory.h',
     ],
     'chrome_browser_web_resource_sources': [
-      'browser/web_resource/chrome_web_resource_service.cc',
-      'browser/web_resource/chrome_web_resource_service.h',
       'browser/web_resource/notification_promo.cc',
       'browser/web_resource/notification_promo.h',
       'browser/web_resource/notification_promo_helper.cc',
       'browser/web_resource/notification_promo_helper.h',
       'browser/web_resource/promo_resource_service.cc',
       'browser/web_resource/promo_resource_service.h',
     ],
     'chrome_browser_webrtc_sources': [
       # TODO(brettw) should webrtc_log_list.cc go here?
       'browser/media/webrtc_log_uploader.cc',
@@ skipping 1035 matching lines @@
             '../components/components.gyp:omnibox_browser',
             '../components/components.gyp:rlz',
             '../components/components.gyp:search_engines',
             '../rlz/rlz.gyp:rlz_lib',
           ],
         },
       ],
     }],
   ],
 }