Allow TranslateRanker to override decisions taken by heuristics.

components/translate/core/browser/translate_ranker_impl.cc

Index: components/translate/core/browser/translate_ranker_impl.cc
diff --git a/components/translate/core/browser/translate_ranker_impl.cc b/components/translate/core/browser/translate_ranker_impl.cc
index 40fd850ff0acdc3ce6055475b0ada9c53cf148b1..139efd104be60018468a304cd7a380700076aeff 100644
--- a/components/translate/core/browser/translate_ranker_impl.cc
+++ b/components/translate/core/browser/translate_ranker_impl.cc
@@ -82,6 +82,9 @@ const base::Feature kTranslateRankerEnforcement{
 const base::Feature kTranslateRankerLogging{"TranslateRankerLogging",
                                             base::FEATURE_ENABLED_BY_DEFAULT};
 
+const base::Feature kTranslateRankerDecisionOverride{
+    "TranslateRankerDecisionOverride", base::FEATURE_DISABLED_BY_DEFAULT};
+
 TranslateRankerFeatures::TranslateRankerFeatures() {}
 
 TranslateRankerFeatures::TranslateRankerFeatures(int accepted,
@@ -138,8 +141,11 @@ TranslateRankerImpl::TranslateRankerImpl(const base::FilePath& model_path,
       is_query_enabled_(base::FeatureList::IsEnabled(kTranslateRankerQuery)),
       is_enforcement_enabled_(
           base::FeatureList::IsEnabled(kTranslateRankerEnforcement)),
+      is_decision_override_enabled_(base::FeatureList::IsEnabled(
+          translate::kTranslateRankerDecisionOverride)),
       weak_ptr_factory_(this) {
-  if (IsQueryEnabled() || IsEnforcementEnabled()) {
+  if (IsQueryEnabled() || IsEnforcementEnabled() ||
+      IsDecisionOverrideEnabled()) {
     model_loader_ = base::MakeUnique<RankerModelLoader>(
         base::Bind(&ValidateModel),
         base::Bind(&TranslateRankerImpl::OnModelAvailable,
@@ -196,6 +202,10 @@ bool TranslateRankerImpl::IsEnforcementEnabled() {
   return is_enforcement_enabled_;
 }
 
+bool TranslateRankerImpl::IsDecisionOverrideEnabled() {
+  return is_decision_override_enabled_;
+}
+
 int TranslateRankerImpl::GetModelVersion() const {
   return model_ ? model_->proto().translate().version() : 0;
 }