The main reason for this is that the Google Chrome logo and related assets is a trademark which we don‘t want to release under Chromium’s open source license.
Therefore, if you want to add a trademarked resource, check it into the internal repository, and pick a resource based on the branding (
is_chrome_branded in GN,
#if defined(GOOGLE_CHROME_BUILD) in cpp). If possible, check an open source version into Chromium, so the feature continues to work as expected in the open source build.
For strings, it’s ok to check them into the open source repository, but make sure that you refer to the correct product, i.e., check in a version of the string that says “Google Chrome” and a version that says “Chromium”.