mac: Simplify initialization of locales_as_mac_outputs.

GN grew a string_replace() function we can use here.

No behavior change.

Bug: none
Change-Id: Ic06e6aa40f4507047bc3cff143af84bc8a99c777
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1773538Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#690843}

build/config/locales.gni

@@ -109,81 +109,23 @@ if (!is_ios) {
     "es-MX",
     "pt",
   ]
-
-  ios_packed_locales = locales - ios_unsupported_locales
 }
 
 locales_with_fake_bidi = locales + [ "fake-bidi" ]
 
 # Same as the locales list but in the format Mac expects for output files:
 # it uses underscores instead of hyphens, and "en" instead of "en-US".
-locales_as_mac_outputs = [
-  "am",
-  "ar",
-  "bg",
-  "bn",
-  "ca",
-  "cs",
-  "da",
-  "de",
-  "el",
-  "en_GB",
-  "en",
-  "es",
-  "et",
-  "fa",
-  "fi",
-  "fil",
-  "fr",
-  "gu",
-  "he",
-  "hi",
-  "hr",
-  "hu",
-  "id",
-  "it",
-  "ja",
-  "kn",
-  "ko",
-  "lt",
-  "lv",
-  "ml",
-  "mr",
-  "ms",
-  "nb",
-  "nl",
-  "pl",
-  "pt_PT",
-  "ro",
-  "ru",
-  "sk",
-  "sl",
-  "sr",
-  "sv",
-  "sw",
-  "ta",
-  "te",
-  "th",
-  "tr",
-  "uk",
-  "vi",
-  "zh_CN",
-  "zh_TW",
-]
-
-# Chrome on iOS uses different names for "es-419" and "pt-BR" (called
-# respectively "es-MX" and "pt" on iOS).
-if (!is_ios) {
-  locales_as_mac_outputs += [
-    "es_419",
-    "pt_BR",
-  ]
-} else {
-  locales_as_mac_outputs += [
-    "es_MX",
-    "pt",
-  ]
+locales_as_mac_outputs = []
+foreach(locale, locales) {
+  if (locale == "en-US") {
+    locales_as_mac_outputs += [ "en" ]
+  } else {
+    locales_as_mac_outputs += [ string_replace(locale, "-", "_") ]
+  }
+}
 
+if (is_ios) {
+  ios_packed_locales = locales - ios_unsupported_locales
   ios_packed_locales_as_mac_outputs =
       locales_as_mac_outputs - ios_unsupported_locales
 }