Introduce HostID and de-couple Extensions from "script injection System" [browser side]

chrome/chrome_tests_unit.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': {
     'chrome_unit_tests_sources': [
       '../apps/saved_files_service_unittest.cc',
       '../components/autofill/content/renderer/test_password_autofill_agent.cc',
       '../components/autofill/content/renderer/test_password_autofill_agent.h',
       '../components/autofill/content/renderer/test_password_generation_agent.cc',
@@ skipping 394 matching lines @@
       'browser/extensions/extension_protocols_unittest.cc',
       'browser/extensions/extension_reenabler_unittest.cc',
       'browser/extensions/extension_service_test_base.h',
       'browser/extensions/extension_service_test_base.cc',
       'browser/extensions/extension_service_unittest.cc',
       'browser/extensions/extension_special_storage_policy_unittest.cc',
       'browser/extensions/extension_sync_data_unittest.cc',
       'browser/extensions/extension_test_message_listener_unittest.cc',
       'browser/extensions/extension_toolbar_model_unittest.cc',
       'browser/extensions/extension_ui_unittest.cc',
+      'browser/extensions/extension_user_script_loader_unittest.cc',
       'browser/extensions/extension_warning_badge_service_unittest.cc',
       'browser/extensions/extension_web_ui_unittest.cc',
       'browser/extensions/external_policy_loader_unittest.cc',
       'browser/extensions/external_provider_impl_chromeos_unittest.cc',
       'browser/extensions/external_provider_impl_unittest.cc',
       'browser/extensions/favicon_downloader_unittest.cc',
       'browser/extensions/install_tracker_unittest.cc',
       'browser/extensions/location_bar_controller_unittest.cc',
       'browser/extensions/menu_manager_unittest.cc',
       'browser/extensions/pack_extension_unittest.cc',
       'browser/extensions/permission_message_combinations_unittest.cc',
       'browser/extensions/permission_messages_unittest.cc',
       'browser/extensions/permissions_based_management_policy_provider_unittest.cc',
       'browser/extensions/permissions_updater_unittest.cc',
       'browser/extensions/policy_handlers_unittest.cc',
       'browser/extensions/sandboxed_unpacker_unittest.cc',
       'browser/extensions/shared_module_service_unittest.cc',
       'browser/extensions/standard_management_policy_provider_unittest.cc',
       'browser/extensions/token_cache/token_cache_service_unittest.cc',
       'browser/extensions/updater/extension_cache_fake.cc',
       'browser/extensions/updater/extension_cache_fake.h',
       'browser/extensions/updater/extension_updater_unittest.cc',
       'browser/extensions/user_script_listener_unittest.cc',
-      'browser/extensions/user_script_loader_unittest.cc',
       'browser/extensions/webstore_inline_installer_unittest.cc',
       'browser/extensions/webstore_installer_unittest.cc',
       'browser/extensions/zipfile_installer_unittest.cc',
       'browser/external_protocol/external_protocol_handler_unittest.cc',
       'browser/favicon/favicon_handler_unittest.cc',
       'browser/file_select_helper_unittest.cc',
       'browser/first_run/first_run_unittest.cc',
       'browser/font_family_cache_unittest.cc',
       'browser/geolocation/geolocation_permission_context_unittest.cc',
       'browser/global_keyboard_shortcuts_mac_unittest.mm',
@@ skipping 2511 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }