[Android] Upstream ChromeNativePreferences as PrefServiceBridge

chrome/browser/android/preferences/pref_service_bridge_unittest.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/android/preferences/pref_service_bridge.h"
+
+#include <string>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+
+// A test class for PrefServiceBridge class.
+class PrefServiceBridgeTest : public testing::Test {
+ public:
+  std::string GetAcceptLanguages(std::string locale,
+                                 std::string accept_languages) {
+    PrependToAcceptLanguagesIfNecessary(locale, &accept_languages);
+    return accept_languages;
+  }
+};
+
+TEST_F(PrefServiceBridgeTest, PrependToAcceptLanguagesAsNecessary) {
+  EXPECT_EQ("ms-MY,ms,en-US,en", GetAcceptLanguages("ms_MY", "en-US,en"));
+
+  EXPECT_EQ("de-CH,de-DE,de,en-US,en",
+      GetAcceptLanguages("de_CH", "de-DE,de,en-US,en"));
+
+  // Make sure we do not prepend language code even when a language code is at
+  // the end.
+  EXPECT_EQ("zh-TW,zh-CN,zh", GetAcceptLanguages("zh_TW", "zh-CN,zh"));
+}
+
+TEST_F(PrefServiceBridgeTest,
+       ShouldNotPrependToAcceptLanguagesWhenNotNecessary) {
+  // Java has some deprecated two letter language code. For instance, "iw" is
+  // an old code that needs to be replaced by "he" which is the new code for
+  // Hebrew.
+  EXPECT_EQ("he-IL,he,en-US,en",
+      GetAcceptLanguages("iw_IL", "he-IL,he,en-US,en"));
+
+  // This logic should not affect cases where original accept language already
+  // reflects the language code in the locale.
+  EXPECT_EQ("en-US,en", GetAcceptLanguages("en_US", "en-US,en"));
+  EXPECT_EQ("zh-CN,zh", GetAcceptLanguages("zh_CN", "zh-CN,zh"));
+
+  // "ms" is not expected. No replacement takes place.
+  EXPECT_EQ("en-US,en", GetAcceptLanguages("ms", "en-US,en"));
+}