This directory contains code that is shared between

• Browser Settings (chrome://settings)
• CrOS Settings (chrome://os-settings)

The pattern used here is referred to as “limited sharing” unlike the chrome://resources approach which is “unlimited sharing”.

This approach has the following advantages over moving shared code under chrome://resources/:

• It allows a limited number of WebUI surfaces to use it, instead of exposing to all WebUI surfaces (hence the “limited sharing” name).
• It also allows leveraging $i18n{} C++ string replacements, which is not possible in cr_elements/ or cr_components/. WebUIs that use the shared code are still responsible for registering all necessary strings.

The “limited sharing” mechanism works as follows

• Code to be shared is built on its own, with a dedicated build_webui() target.
• The resulting grd file entries kSettingsSharedResources are included in the build once and registered at runtime under all WebUIDataSource instances that need to use this code.
• Shared code is exposed under /shared/settings/* URLs (same as chrome://settings/shared/settings/ or chrome://os-settings/shared/settings/ respectively).
• build_webui()'s ts_path_mappings and optimize_webui_external_paths parameters are leveraged so that the respective underlying tools (TS compiler and Rollup) can correctly resolve such paths.

A similar approach is also followed in c/b/r/side_panel/shared.

Note: The files in this folder are only added as standalone files to the build when optimize_webui=false. In other cases the same files are already bundled within the UIs that use them and therefore adding them as standalone files is unnecessary.