Add variations params api to get params from features.

components/variations/variations_associated_data.cc

 // Copyright 2013 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/variations/variations_associated_data.h"
 
 #include <map>
 #include <utility>
 #include <vector>
 
+#include "base/feature_list.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 
 namespace variations {
 
 namespace {
 
 // The internal singleton accessor for the map, used to keep it thread-safe.
 class GroupMapAccessor {
  public:
@@ skipping 184 matching lines @@
   return VariationsParamAssociator::GetInstance()->AssociateVariationParams(
       trial_name, group_name, params);
 }
 
 bool GetVariationParams(const std::string& trial_name,
                         std::map<std::string, std::string>* params) {
   return VariationsParamAssociator::GetInstance()->GetVariationParams(
       trial_name, params);
 }
 
+bool GetVariationParamsByFeature(const base::Feature& feature,
+                                 std::map<std::string, std::string>* params) {
+  if (!base::FeatureList::IsEnabled(feature))
+    return false;
+
+  base::FieldTrial* trial = base::FeatureList::GetFieldTrial(feature);
+  if (!trial)
+    return false;
+
+  return GetVariationParams(trial->trial_name(), params);
+}
+
 std::string GetVariationParamValue(const std::string& trial_name,
                                    const std::string& param_name) {
   std::map<std::string, std::string> params;
   if (GetVariationParams(trial_name, &params)) {
     std::map<std::string, std::string>::iterator it = params.find(param_name);
     if (it != params.end())
       return it->second;
   }
   return std::string();
 }
 
+std::string GetVariationParamValueByFeature(const base::Feature& feature,
+                                            const std::string& param_name) {
+  if (!base::FeatureList::IsEnabled(feature))
+    return std::string();
+
+  base::FieldTrial* trial = base::FeatureList::GetFieldTrial(feature);
+  if (!trial)
+    return std::string();
+
+  return GetVariationParamValue(trial->trial_name(), param_name);
+}
+
 // Functions below are exposed for testing explicitly behind this namespace.
 // They simply wrap existing functions in this file.
 namespace testing {
 
 void ClearAllVariationIDs() {
   GroupMapAccessor::GetInstance()->ClearAllMapsForTesting();
 }
 
 void ClearAllVariationParams() {
   VariationsParamAssociator::GetInstance()->ClearAllParamsForTesting();
 }
 
 }  // namespace testing
 
 }  // namespace variations