Build a few more extensions files only when extensions are enabled.

chrome/chrome_common.gypi

 # Copyright (c) 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': {
     # File lists shared with GN build.
     'chrome_common_sources': [
       'common/all_messages.h',
       'common/attrition_experiments.h',
@@ skipping 37 matching lines @@
       'common/content_settings_pattern_serializer.h',
       'common/crash_keys.cc',
       'common/crash_keys.h',
       'common/custom_handlers/protocol_handler.cc',
       'common/custom_handlers/protocol_handler.h',
       'common/descriptors_android.h',
       'common/extensions/chrome_extension_messages.h',
       'common/extensions/chrome_extensions_client.cc',
       'common/extensions/chrome_extensions_client.h',
       'common/extensions/chrome_utility_extensions_messages.h',
-      'common/extensions/command.cc',
-      'common/extensions/command.h',
       'common/extensions/extension_constants.cc',
       'common/extensions/extension_constants.h',
-      'common/extensions/extension_process_policy.cc',
-      'common/extensions/extension_process_policy.h',
       'common/extensions/features/chrome_channel_feature_filter.cc',
       'common/extensions/features/chrome_channel_feature_filter.h',
       'common/extensions/features/feature_channel.cc',
       'common/extensions/features/feature_channel.h',
-      'common/extensions/image_writer/image_writer_util_mac.cc',
-      'common/extensions/image_writer/image_writer_util_mac.h',
       'common/extensions/permissions/chrome_api_permissions.cc',
       'common/extensions/permissions/chrome_api_permissions.h',
       'common/extensions/permissions/chrome_permission_message_provider.cc',
       'common/extensions/permissions/chrome_permission_message_provider.h',
-      'common/extensions/sync_helper.cc',
-      'common/extensions/sync_helper.h',
       'common/favicon/favicon_url_parser.cc',
       'common/favicon/favicon_url_parser.h',
       'common/icon_with_badge_image_source.cc',
       'common/icon_with_badge_image_source.h',
       'common/ini_parser.cc',
       'common/ini_parser.h',
       'common/instant_restricted_id_cache.h',
       'common/instant_types.cc',
       'common/instant_types.h',
       'common/localized_error.cc',
@@ skipping 93 matching lines @@
       'common/extensions/api/system_indicator/system_indicator_handler.cc',
       'common/extensions/api/system_indicator/system_indicator_handler.h',
       'common/extensions/api/url_handlers/url_handlers_parser.cc',
       'common/extensions/api/url_handlers/url_handlers_parser.h',
       'common/extensions/api/webstore/webstore_api_constants.cc',
       'common/extensions/api/webstore/webstore_api_constants.h',
       'common/extensions/chrome_manifest_handlers.cc',
       'common/extensions/chrome_manifest_handlers.h',
       'common/extensions/chrome_manifest_url_handlers.cc',
       'common/extensions/chrome_manifest_url_handlers.h',
+      'common/extensions/command.cc',
+      'common/extensions/command.h',
       'common/extensions/extension_file_util.cc',
       'common/extensions/extension_file_util.h',
+      'common/extensions/extension_process_policy.cc',
+      'common/extensions/extension_process_policy.h',
+      'common/extensions/image_writer/image_writer_util_mac.cc',
+      'common/extensions/image_writer/image_writer_util_mac.h',
       'common/extensions/manifest_handlers/app_isolation_info.cc',
       'common/extensions/manifest_handlers/app_isolation_info.h',
       'common/extensions/manifest_handlers/app_launch_info.cc',
       'common/extensions/manifest_handlers/app_launch_info.h',
       'common/extensions/manifest_handlers/automation.cc',
       'common/extensions/manifest_handlers/automation.h',
       'common/extensions/manifest_handlers/content_scripts_handler.cc',
       'common/extensions/manifest_handlers/content_scripts_handler.h',
       'common/extensions/manifest_handlers/extension_action_handler.cc',
       'common/extensions/manifest_handlers/extension_action_handler.h',
       'common/extensions/manifest_handlers/mime_types_handler.cc',
       'common/extensions/manifest_handlers/mime_types_handler.h',
       'common/extensions/manifest_handlers/minimum_chrome_version_checker.cc',
       'common/extensions/manifest_handlers/minimum_chrome_version_checker.h',
       'common/extensions/manifest_handlers/settings_overrides_handler.cc',
       'common/extensions/manifest_handlers/settings_overrides_handler.h',
       'common/extensions/manifest_handlers/theme_handler.cc',
       'common/extensions/manifest_handlers/theme_handler.h',
       'common/extensions/manifest_handlers/ui_overrides_handler.cc',
       'common/extensions/manifest_handlers/ui_overrides_handler.h',
+      'common/extensions/sync_helper.cc',
+      'common/extensions/sync_helper.h',
     ],
     'chrome_common_full_safe_browsing_sources': [
       'common/safe_browsing/download_protection_util.cc',
       'common/safe_browsing/download_protection_util.h',
       'common/safe_browsing/zip_analyzer.cc',
       'common/safe_browsing/zip_analyzer.h',
     ],
     'chrome_common_importer_sources': [
       'common/importer/firefox_importer_utils.cc',
       'common/importer/firefox_importer_utils.h',
@@ skipping 458 matching lines @@
         'common/safe_browsing/csd.proto'
       ],
       'variables': {
         'proto_in_dir': 'common/safe_browsing',
         'proto_out_dir': 'chrome/common/safe_browsing',
       },
       'includes': [ '../build/protoc.gypi' ],
     },
   ],
 }