WORK IN PROGRESS.

chrome/chrome_browser.gypi

Index: chrome/chrome_browser.gypi
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index b4c1ad8d961bb7a9b93091fcab87ab2d49e8b8a7..7607cbfdb85830f0405346b553d5be41aa37f424 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1074,6 +1074,10 @@
         'browser/extensions/extension_settings_storage_cache.h',
         'browser/extensions/extension_settings_leveldb_storage.cc',
         'browser/extensions/extension_settings_leveldb_storage.h',
+        'browser/extensions/extension_settings_sync_data.cc',
+        'browser/extensions/extension_settings_sync_data.h',
+        'browser/extensions/extension_settings_sync_helper.cc',
+        'browser/extensions/extension_settings_sync_helper.h',
         'browser/extensions/extension_service.cc',
         'browser/extensions/extension_service.h',
         'browser/extensions/extension_sidebar_api.cc',
@@ -1159,6 +1163,8 @@
         'browser/extensions/pending_extension_manager.h',
         'browser/extensions/sandboxed_extension_unpacker.cc',
         'browser/extensions/sandboxed_extension_unpacker.h',
+        'browser/extensions/syncable_extension_settings_storage.cc',
+        'browser/extensions/syncable_extension_settings_storage.h',
         'browser/extensions/theme_installed_infobar_delegate.cc',
         'browser/extensions/theme_installed_infobar_delegate.h',
         'browser/extensions/user_script_listener.cc',
@@ -2077,6 +2083,8 @@
         'browser/sync/glue/extension_data_type_controller.h',
         'browser/sync/glue/extension_model_associator.cc',
         'browser/sync/glue/extension_model_associator.h',
+        'browser/sync/glue/extension_setting_data_type_controller.cc',
+        'browser/sync/glue/extension_setting_data_type_controller.h',
         'browser/sync/glue/extension_sync.cc',
         'browser/sync/glue/extension_sync.h',
         'browser/sync/glue/extension_sync_traits.cc',