Worked on improving locale handling in the microsoft/playwright repository by delivering a targeted bug fix for Firefox browser patches. Addressed an issue where the ICU locale header was not included when using the system ICU, which previously hindered proper support for the JavaScript Internationalization API. The solution involved removing a conditional check that prevented necessary headers from being included, thereby enabling more reliable locale support across environments and reducing test flakiness related to internationalization. Utilized C++ and applied expertise in browser development and internationalization to ensure that locale-dependent features functioned correctly when the Intl API was enabled in Firefox.