Allow TranslateRanker to override decisions taken by heuristics.

chrome/browser/translate/chrome_translate_client.cc

Index: chrome/browser/translate/chrome_translate_client.cc
diff --git a/chrome/browser/translate/chrome_translate_client.cc b/chrome/browser/translate/chrome_translate_client.cc
index 53110c1049952b43f127482fbe670c56ce55931f..ef564bd73092ea48577cbdf6a8d7a8a63ede2023 100644
--- a/chrome/browser/translate/chrome_translate_client.cc
+++ b/chrome/browser/translate/chrome_translate_client.cc
@@ -36,6 +36,7 @@
 #include "components/translate/core/browser/translate_infobar_delegate.h"
 #include "components/translate/core/browser/translate_manager.h"
 #include "components/translate/core/browser/translate_prefs.h"
+#include "components/translate/core/browser/translate_ranker.h"
 #include "components/translate/core/common/language_detection_details.h"
 #include "components/variations/service/variations_service.h"
 #include "content/public/browser/notification_service.h"
@@ -224,18 +225,31 @@ void ChromeTranslateClient::ShowTranslateUI(
     // another page.
     if (!base::FeatureList::IsEnabled(translate::kTranslateUI2016Q2) &&
         !GetLanguageState().HasLanguageChanged()) {
-      translate_manager_->RecordTranslateEvent(
-          metrics::TranslateEventProto::MATCHES_PREVIOUS_LANGUAGE);
-      return;
+      if (translate::TranslateRanker::IsDecisionOverrideEnabled()) {
+        translate_manager_->RecordDecisionOverride(
+            metrics::TranslateEventProto::MATCHES_PREVIOUS_LANGUAGE);
+        DVLOG(3) << "Overriding decision MATCHES_PREVIOUS_LANGUAGE.";
+      } else {
+        translate_manager_->RecordTranslateEvent(
+            metrics::TranslateEventProto::MATCHES_PREVIOUS_LANGUAGE);
+        return;
+      }
     }
 
     if (!triggered_from_menu &&
         GetTranslatePrefs()->IsTooOftenDenied(source_language)) {
-      translate_manager_->RecordTranslateEvent(
-          metrics::TranslateEventProto::LANGUAGE_DISABLED_BY_AUTO_BLACKLIST);
-      return;
+      if (translate::TranslateRanker::IsDecisionOverrideEnabled()) {

[groby-ooo-7-16, 2017/02/23 19:08:06]

You could filter out the common code into a helper, which would result in both
instances becoming something like

if (DecisionOverride(MATCHES_PREVIOUS_LANGUAGE))
  return;

making things somewhat more readable.

[hamelphi, 2017/03/01 00:40:03]

Done. I moved the logging logic to TranslateManager.

+        translate_manager_->RecordDecisionOverride(
+            metrics::TranslateEventProto::LANGUAGE_DISABLED_BY_AUTO_BLACKLIST);
+        DVLOG(3) << "Overriding decision LANGUAGE_DISABLED_BY_AUTO_BLACKLIST.";
+      } else {
+        translate_manager_->RecordTranslateEvent(
+            metrics::TranslateEventProto::LANGUAGE_DISABLED_BY_AUTO_BLACKLIST);
+        return;
+      }
     }
   }
+
   ShowTranslateBubbleResult result = ShowBubble(step, error_type);
   if (result != ShowTranslateBubbleResult::SUCCESS &&
       step == translate::TRANSLATE_STEP_BEFORE_TRANSLATE) {