Remove ImageLoadingTracker class

chrome/chrome_browser_extensions.gypi

 # Copyright (c) 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.
 
 {
   'targets': [
     {
       'target_name': 'browser_extensions',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 603 matching lines @@
         'browser/extensions/external_provider_impl.h',
         'browser/extensions/external_provider_interface.h',
         'browser/extensions/external_registry_loader_win.cc',
         'browser/extensions/external_registry_loader_win.h',
         'browser/extensions/file_reader.cc',
         'browser/extensions/file_reader.h',
         'browser/extensions/image_loader.cc',
         'browser/extensions/image_loader.h',
         'browser/extensions/image_loader_factory.cc',
         'browser/extensions/image_loader_factory.h',
-        'browser/extensions/image_loading_tracker.cc',
-        'browser/extensions/image_loading_tracker.h',
         'browser/extensions/installed_loader.cc',
         'browser/extensions/installed_loader.h',
         'browser/extensions/key_identifier_conversion_views.cc',
         'browser/extensions/key_identifier_conversion_views.h',
         'browser/extensions/lazy_background_task_queue.cc',
         'browser/extensions/lazy_background_task_queue.h',
         'browser/extensions/location_bar_controller.h',
         'browser/extensions/management_policy.cc',
         'browser/extensions/management_policy.h',
         'browser/extensions/manifest_url_parser.cc',
@@ skipping 323 matching lines @@
           'variables': {
             'proto_in_dir': 'browser/chromeos/contacts',
             'proto_out_dir': 'chrome/browser/chromeos/contacts',
           },
           'includes': [ '../build/protoc.gypi' ]
         },
       ],
     },],  # 'chromeos=1'
   ],  # 'conditions'
 }