Bug 40199: Avoid using system locale for intl.accept_languages in GeckoView

    private String computeAcceptLanguages() {

        ArrayList<String> locales = new ArrayList<String>();

        // Explicitly-set app prefs come first:

        if (mRequestedLocales != null) {

            for (String locale : mRequestedLocales) {

                locales.add(locale.toLowerCase());

        // In Desktop, these are defined in the `intl.accept_languages` localized property.

        // At some point we should probably use the same values here, but for now we use a simple

        // strategy which will hopefully result in reasonable acceptLanguage values.

        if (mRequestedLocales != null && mRequestedLocales.length > 0) {

            String locale = mRequestedLocales[0].toLowerCase();

            // No need to include `en-us` twice.

            if (!locale.equals("en-us")) {

                locales.add(locale);

                if (locale.contains("-")) {

                    String lang = locale.split("-")[0];

                    // No need to include `en` twice.

                    if (!lang.equals("en")) {

                        locales.add(lang);

                    }

                }

        // OS prefs come second:

        for (String locale : getDefaultLocales()) {

            locale = locale.toLowerCase();

            if (!locales.contains(locale)) {

                locales.add(locale);

            }

        }

        locales.add("en-us");

        locales.add("en");

        return TextUtils.join(",", locales);

    }