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

extensions/extensions.gyp

 # Copyright 2013 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': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 70 matching lines @@
         'common/api/sockets/sockets_manifest_data.cc',
         'common/api/sockets/sockets_manifest_data.h',
         'common/api/sockets/sockets_manifest_handler.cc',
         'common/api/sockets/sockets_manifest_handler.h',
         'common/api/sockets/sockets_manifest_permission.cc',
         'common/api/sockets/sockets_manifest_permission.h',
         'common/cast/cast_cert_validator.cc',
         'common/cast/cast_cert_validator.h',
         'common/common_manifest_handlers.cc',
         'common/common_manifest_handlers.h',
+        'common/host_id.h',
         'common/csp_validator.cc',
         'common/csp_validator.h',
         'common/dom_action_types.h',
         'common/draggable_region.cc',
         'common/draggable_region.h',
         'common/error_utils.cc',
         'common/error_utils.h',
         'common/event_filter.cc',
         'common/event_filter.h',
         'common/event_filtering_info.cc',
@@ skipping 1079 matching lines @@
               '<(SHARED_INTERMEDIATE_DIR)/blink/devtools_resources.pak',
             ],
             'pak_output': '<(PRODUCT_DIR)/extensions_shell_and_test.pak',
           },
           'includes': [ '../build/repack_action.gypi' ],
         },
       ],
     },
   ]
 }