Don't offer to translate between Simplified and Traditional Chinese

components/translate/core/browser/translate_manager_unittest.cc

Index: components/translate/core/browser/translate_manager_unittest.cc
diff --git a/components/translate/core/browser/translate_manager_unittest.cc b/components/translate/core/browser/translate_manager_unittest.cc
index fda38d798ab21257c32a8274876b62fa875d7958..e1b4e8ef35dd06fd7abb429615efa7e9bf03061d 100644
--- a/components/translate/core/browser/translate_manager_unittest.cc
+++ b/components/translate/core/browser/translate_manager_unittest.cc
@@ -307,6 +307,54 @@ TEST_F(TranslateManagerTest, DontTranslateOffline) {
       1);
 }
 
+// The test measures that Translate is not triggered for a zh-TW page for a
+// zh-CN user.
+TEST_F(TranslateManagerTest,
+       DontTranslateZhTraditionalPageForZhSimplifiedLocale) {
+  TranslateManager::SetIgnoreMissingKeyForTesting(true);
+  translate_manager_.reset(new translate::TranslateManager(
+      &mock_translate_client_, kAcceptLanguages));
+
+  const char kMetricName[] = "Translate.InitiationStatus.v2";
+  base::HistogramTester histogram_tester;
+
+  const std::string locale = "zh-TW";
+  const std::string page_lang = "zh-CN";
+  manager_->set_application_locale(locale);
+  translate_manager_->GetLanguageState().LanguageDetermined(page_lang, true);
+
+  translate_manager_->InitiateTranslation(page_lang);
+  histogram_tester.ExpectTotalCount(kMetricName, 0);

[groby-ooo-7-16, 2017/01/25 16:20:10]

That's the offending line, sorry for not spotting it in the review. You expect a
total count of 1 sample in the histogram, not 0. (You can just  delete this -
ExpectUniqueSample tests there is exactly one sample added)

Both here and below.

+  histogram_tester.ExpectUniqueSample(
+      kMetricName,
+      translate::TranslateBrowserMetrics::INITIATION_STATUS_SIMILAR_LANGUAGES,
+      1);
+}
+
+// The test measures that Translate is not triggered for a zh-CN page for a
+// zh-TW user.
+TEST_F(TranslateManagerTest,
+       DontTranslateZhSimplifiedPageForZhTraditionalLocale) {
+  TranslateManager::SetIgnoreMissingKeyForTesting(true);
+  translate_manager_.reset(new translate::TranslateManager(
+      &mock_translate_client_, kAcceptLanguages));
+
+  const char kMetricName[] = "Translate.InitiationStatus.v2";
+  base::HistogramTester histogram_tester;
+
+  const std::string locale = "zh-CN";
+  const std::string page_lang = "zh-TW";
+  manager_->set_application_locale(locale);
+  translate_manager_->GetLanguageState().LanguageDetermined(page_lang, true);
+
+  translate_manager_->InitiateTranslation(page_lang);
+  histogram_tester.ExpectTotalCount(kMetricName, 0);
+  histogram_tester.ExpectUniqueSample(
+      kMetricName,
+      translate::TranslateBrowserMetrics::INITIATION_STATUS_SIMILAR_LANGUAGES,
+      1);
+}
+
 // Utility function to set the threshold params
 void ChangeThresholdInParams(
     const char* initiate_translation_confidence_threshold,