using ulp to improve TranslateManager GetTargetLanguage() and InitiateTranslation()

components/translate/core/browser/translate_prefs.cc

Index: components/translate/core/browser/translate_prefs.cc
diff --git a/components/translate/core/browser/translate_prefs.cc b/components/translate/core/browser/translate_prefs.cc
index 98419c0c91474d127ccef774ead2cf8f0f123a91..ed57e985d6a84ce90cf3491b52e7cd6a0d1db949 100644
--- a/components/translate/core/browser/translate_prefs.cc
+++ b/components/translate/core/browser/translate_prefs.cc
@@ -20,6 +20,7 @@
 
 namespace translate {
 
+const char TranslatePrefs::kPrefLanguageProfile[] = "language_profile";
 const char TranslatePrefs::kPrefTranslateSiteBlacklist[] =
     "translate_site_blacklist";
 const char TranslatePrefs::kPrefTranslateWhitelists[] = "translate_whitelists";
@@ -35,10 +36,18 @@ const char TranslatePrefs::kPrefTranslateLastDeniedTimeForLanguage[] =
     "translate_last_denied_time_for_language";
 const char TranslatePrefs::kPrefTranslateTooOftenDeniedForLanguage[] =
     "translate_too_often_denied_for_language";
+
 const char kTranslateUI2016Q2TrialName[] = "TranslateUI2016Q2";
 const char kAlwaysTranslateOfferThreshold[] =
     "always_translate_offer_threshold";
 
+// For reading ULP prefs.
+const char kConfidence[] = "confidence";
+const char kLanguage[] = "language";
+const char kPreference[] = "preference";
+const char kProbability[] = "probability";
+const char kReading[] = "reading";
+
 // The below properties used to be used but now are deprecated. Don't use them
 // since an old profile might have some values there.
 //
@@ -474,6 +483,8 @@ void TranslatePrefs::RegisterProfilePrefs(
   registry->RegisterDictionaryPref(
       kPrefTranslateTooOftenDeniedForLanguage,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterDictionaryPref(
+      kPrefLanguageProfile, user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 }
 
 // static
@@ -569,4 +580,58 @@ bool TranslatePrefs::IsDictionaryEmpty(const char* pref_id) const {
   return (dict == NULL || dict->empty());
 }
 
+double TranslatePrefs::GetReadingFromUserLanguageProfile(
+    LanguageAndProbabilityList* out_value) const {
+  const base::DictionaryValue* dict =
+      prefs_->GetDictionary(kPrefLanguageProfile);
+  const base::DictionaryValue* entries = nullptr;
+
+  // Return 0.0 if no ULP prefs.
+  if (!dict)
+    return 0.0;
+
+  // Return 0.0 if no such list.
+  if (!dict->GetDictionary(kReading, &entries))
+    return 0.0;
+
+  double confidence = 0.0;
+  // Return 0.0 if cannot find confidence.
+  if (!entries->GetDouble(kConfidence, &confidence))
+    return 0.0;
+
+  const base::ListValue* preference = nullptr;
+  // Return the confidence if there are no item on the 'preference' field.
+  if (!entries->GetList(kPreference, &preference))
+    return confidence;
+
+  // Use a map to fold the probability of all the same normalized language
+  // code together.
+  std::map<std::string, double> probability_map;
+  // Iterate through the preference.
+  for (const auto& entry : *preference) {
+    const base::DictionaryValue* item = nullptr;
+    std::string language;
+    double probability = 0.0;
+    if (entry->GetAsDictionary(&item) &&
+        item->GetString(kLanguage, &language) &&
+        item->GetDouble(kProbability, &probability)) {
+      // Normalize the the language code known and supported by
+      // Translate.
+      translate::ToTranslateLanguageSynonym(&language);
+      // Discard if the normalized version is unsupported.
+      if (TranslateDownloadManager::IsSupportedLanguage(language)) {
+        probability_map[language] += probability;
+      }
+    }
+  }
+  for (const auto& it : probability_map)
+    out_value->push_back(it);
+  std::sort(out_value->begin(), out_value->end(),
+            [](const LanguageAndProbability& left,
+               const LanguageAndProbability& right) {
+              return left.second > right.second;
+            });
+  return confidence;
+}
+
 }  // namespace translate