Issue 5860 - options page is broken in test enviroment

ext/common.js

Index: ext/common.js
===================================================================
--- a/ext/common.js
+++ b/ext/common.js
@@ -83,16 +83,16 @@
   let getLocaleCandidates = function(selectedLocale)
   {
     let candidates = [];
-    let defaultLocale = "en-US";
+    let defaultLocale = "en_US";
 
-    // e.g. "ja-jp-mac" -> "ja-JP", note that the part after the second
+    // e.g. "ja_jp_mac" -> "ja_JP", note that the part after the second
     // dash is dropped, since we only support language and region
-    let parts = selectedLocale.split("-");
+    let parts = selectedLocale.split("_");
     let language = parts[0];
     let region = (parts[1] || "").toUpperCase();
 
     if (region)
-      candidates.push(language + "-" + region);
+      candidates.push(language + "_" + region);
 
     candidates.push(language);
 
@@ -103,7 +103,7 @@
   };
 
   let selectedLocale = window.navigator.language;
-  let match = /[?&]locale=([\w-]+)/.exec(window.location.search);
+  let match = /[?&]locale=([\w_]+)/.exec(window.location.search);
   if (match)
     selectedLocale = match[1];
 
@@ -164,7 +164,7 @@
   chrome.i18n = {
     getUILanguage()
     {
-      return locales[0].replace(/_/g, "-");
+      return locales[0];
     },
     getMessage(msgId, substitutions)
     {