Extend with a language code in http accept languages

net/http/http_util_icu_unittest.cc

+// Copyright (c) 2016 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 "net/http/http_util_icu.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+
+TEST(HttpUtilIcuTest, GenerateAcceptLanguageHeader) {
+  EXPECT_EQ(std::string("en-US,en;q=0.8,fr;q=0.6,de;q=0.4"),
+            HttpUtilIcu::GenerateAcceptLanguageHeader("en-US,fr,de"));
+
+  // Test whitespace between language tags.
+  EXPECT_EQ(std::string("en-US,en;q=0.8,fr;q=0.6,de;q=0.4"),
+            HttpUtilIcu::GenerateAcceptLanguageHeader("en-US,     fr,   de"));
+
+  // Test a language code is inserted after languageTag only if it is not
+  // already in the request language list
+  EXPECT_EQ(std::string("en-US,en;q=0.8,fr-FR;q=0.6,fr;q=0.4,zh-CN;q=0.2,"
+                        "zh;q=0.2"),
+            HttpUtilIcu::GenerateAcceptLanguageHeader("en-US,fr-FR,zh-CN"));
+
+  // Test a language code will not be inserted after languageTag if it is
+  // already in the request language list
+  EXPECT_EQ(std::string("en-US,en;q=0.8,fr-FR;q=0.6,fr;q=0.4,zh-CN;q=0.2,"
+                        "zh;q=0.2"),
+            HttpUtilIcu::GenerateAcceptLanguageHeader("en-US,fr-FR,fr,zh-CN"));
+
+  // Make sure a language code is only inserted after the last languageTag that
+  // contains that language.
+  EXPECT_EQ(std::string("en-US,en-GB;q=0.8,en;q=0.6,fr;q=0.4,zh-CN;q=0.2,"
+                        "zh;q=0.2"),
+            HttpUtilIcu::GenerateAcceptLanguageHeader("en-US,en-GB,fr,zh-CN"));
+}
+}