Default to current UI locale when recommended locales are invalid

chrome/browser/ui/webui/chromeos/login/l10n_util_unittest.cc

Index: chrome/browser/ui/webui/chromeos/login/l10n_util_unittest.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/l10n_util_unittest.cc b/chrome/browser/ui/webui/chromeos/login/l10n_util_unittest.cc
index 86e3d922a1c91c03465558d6eb0b0441ed9eea70..06a25c99f28146aef89142648ddb2651a793a3ef 100644
--- a/chrome/browser/ui/webui/chromeos/login/l10n_util_unittest.cc
+++ b/chrome/browser/ui/webui/chromeos/login/l10n_util_unittest.cc
@@ -129,6 +129,37 @@ TEST_F(L10nUtilTest, GetUILanguageList) {
   VerifyOnlyUILanguages(*list);
 }
 
+TEST_F(L10nUtilTest, FindMostRelevantLocale) {
+  base::ListValue available_locales;
+  available_locales.AppendString("de");
+  available_locales.AppendString("fr");
+  available_locales.AppendString("en-GB");
+
+  EXPECT_EQ("en-US", FindMostRelevantLocale(NULL,
+                                            available_locales,
+                                            "en-US"));
+
+  std::vector<std::string> most_relevant_language_codes;
+  EXPECT_EQ("en-US", FindMostRelevantLocale(&most_relevant_language_codes,
+                                            available_locales,
+                                            "en-US"));
+
+  most_relevant_language_codes.push_back("xx");
+  EXPECT_EQ("en-US", FindMostRelevantLocale(&most_relevant_language_codes,
+                                            available_locales,
+                                            "en-US"));
+
+  most_relevant_language_codes.push_back("fr");
+  EXPECT_EQ("fr", FindMostRelevantLocale(&most_relevant_language_codes,
+                                         available_locales,
+                                         "en-US"));
+
+  most_relevant_language_codes.push_back("de");
+  EXPECT_EQ("fr", FindMostRelevantLocale(&most_relevant_language_codes,
+                                         available_locales,
+                                         "en-US"));
+}
+
 void InitStartupCustomizationDocumentForTesting(const std::string& manifest) {
   StartupCustomizationDocument::GetInstance()->LoadManifestFromString(manifest);
   StartupCustomizationDocument::GetInstance()->Init(