The dupe checker script finds a whole bunch of locale files that are duplicates: see Bug 1313640. Android is unique in that our app bundles all of our locales in a single build. In situations where: - The file is a duplicate of the en-US version, and - The calling code falls back to en-US (which is the case for strings and probably most other content) we can eliminate the per-locale file from the build entirely. Bug 1313640 indicates that there might be noticeable APK size reductions from doing so.

Too late for firefox 52, mass-wontfix.

The new L10n API which we're working toward right now gets rid of the notion of "l10n-merge" and in result files will not be duplicated across locales. Instead, it provides a fallback mechanism which looks up the next locale in case the previous doesn't have a requested resource.

Re-triaging per https://bugzilla.mozilla.org/show_bug.cgi?id=1473195 Needinfo :susheel if you think this bug should be re-triaged.