Don't offer to translate between Simplified and Traditional Chinese

components/translate/core/browser/translate_manager_unittest.cc

 // Copyright 2015 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 "components/translate/core/browser/translate_manager.h"
 
 #include "base/json/json_reader.h"
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
 #include "base/test/histogram_tester.h"
@@ skipping 289 matching lines @@
 
   // In the online case, InitiateTranslation will proceed past early out tests.
   network_notifier_.SimulateOnline();
   translate_manager_->InitiateTranslation("de");
   histogram_tester.ExpectUniqueSample(
       kMetricName,
       translate::TranslateBrowserMetrics::INITIATION_STATUS_DISABLED_BY_PREFS,
       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,
     const char* initiate_translation_probability_threshold,
     const char* target_language_confidence_threshold,
     const char* target_language_probability_threshold) {
   ASSERT_TRUE(variations::AssociateVariationParams(
       kTrialName, "Enabled", {{"initiate_translation_ulp_confidence_threshold",
                                initiate_translation_confidence_threshold},
                               {"initiate_translation_ulp_probability_threshold",
@@ skipping 125 matching lines @@
   // 0.79 and lower than 0.8 and the probability threshold is lower than both
   // the one with "fr" (0.6) and "pt-PT" (0.4).
   EXPECT_TRUE(CallLanguageInULP("fr"));
   EXPECT_TRUE(CallLanguageInULP("pt"));
   EXPECT_FALSE(CallLanguageInULP("zh-TW"));
 }
 
 }  // namespace testing
 
 }  // namespace translate