Record language usage as UMA histograms.

Record accept languages and application language as UMA histograms on
browser start-up.

See also http://crosbug.com/17419

BUG=none
TEST=run the unit tests


Review URL: http://codereview.chromium.org/7348004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@93360 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 91 insertions, 0 deletions

diff --git a/chrome/browser/language_usage_metrics_unittest.cc b/chrome/browser/language_usage_metrics_unittest.cc
new file mode 100644
index 0000000..db6e987
--- /dev/null
+++ b/chrome/browser/language_usage_metrics_unittest.cc
@@ -0,0 +1,91 @@
+// Copyright (c) 2011 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/language_usage_metrics.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(LanguageUsageMetricsTest, ParseAcceptLanguages) {
+  std::set<Language> language_set;
+  std::set<Language>::const_iterator it;
+
+  // Basic single language case.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // Empty language.
+  LanguageUsageMetrics::ParseAcceptLanguages("", &language_set);
+  EXPECT_EQ(0U, language_set.size());
+
+  // Country code is ignored.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja-JP", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // Case is ignored.
+  LanguageUsageMetrics::ParseAcceptLanguages("Ja-jP", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // Underscore as the separator.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja_JP", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // The result contains a same language code only once.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja-JP,ja", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // Basic two languages case.
+  LanguageUsageMetrics::ParseAcceptLanguages("en,ja", &language_set);
+  EXPECT_EQ(2U, language_set.size());
+  it = language_set.begin();
+  EXPECT_EQ(ENGLISH, *it);
+  EXPECT_EQ(JAPANESE, *++it);
+
+  // Multiple languages.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja-JP,en,es,ja,en-US",
+                                             &language_set);
+  EXPECT_EQ(3U, language_set.size());
+  it = language_set.begin();
+  EXPECT_EQ(ENGLISH, *it);
+  EXPECT_EQ(JAPANESE, *++it);
+  EXPECT_EQ(SPANISH, *++it);
+
+  // Two empty languages.
+  LanguageUsageMetrics::ParseAcceptLanguages(",", &language_set);
+  EXPECT_EQ(0U, language_set.size());
+
+  // Trailing comma.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja,", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // Leading comma.
+  LanguageUsageMetrics::ParseAcceptLanguages(",es", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(SPANISH, *language_set.begin());
+
+  // Combination of invalid and valid.
+  LanguageUsageMetrics::ParseAcceptLanguages("zz,en", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(ENGLISH, *language_set.begin());
+}
+
+TEST(LanguageUsageMetricsTest, ToLanguage) {
+  // Basic case.
+  EXPECT_EQ(JAPANESE, LanguageUsageMetrics::ToLanguage("ja"));
+
+  // Case is ignored.
+  EXPECT_EQ(SPANISH, LanguageUsageMetrics::ToLanguage("Es"));
+
+  // Coutry code is ignored.
+  EXPECT_EQ(JAPANESE, LanguageUsageMetrics::ToLanguage("ja-JP"));
+
+  // Invalid locales are considered as unknown language.
+  EXPECT_EQ(UNKNOWN_LANGUAGE, LanguageUsageMetrics::ToLanguage(""));
+  EXPECT_EQ(UNKNOWN_LANGUAGE, LanguageUsageMetrics::ToLanguage("xx"));
+}