Use std::unique_ptr for base::DictionaryValue and base::ListValue's internal store.

extensions/common/features/base_feature_provider.cc

 // Copyright 2014 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 "extensions/common/features/base_feature_provider.h"
 
 #include <stddef.h>
 
 #include <stack>
 #include <utility>
@@ skipping 100 matching lines @@
     } else if (iter.value().GetType() == base::Value::TYPE_LIST) {
       // This is a complex feature.
       const base::ListValue* list =
           static_cast<const base::ListValue*>(&iter.value());
       CHECK_GT(list->GetSize(), 0UL);
 
       std::unique_ptr<ComplexFeature::FeatureList> features(
           new ComplexFeature::FeatureList());
 
       // Parse and add all SimpleFeatures from the list.
-      for (base::ListValue::const_iterator list_iter = list->begin();
-           list_iter != list->end(); ++list_iter) {
-        if ((*list_iter)->GetType() != base::Value::TYPE_DICTIONARY) {
+      for (const auto& entry : *list) {
+        base::DictionaryValue* dict;
+        if (!entry->GetAsDictionary(&dict)) {
           LOG(ERROR) << iter.key() << ": Feature rules must be dictionaries.";
           continue;
         }
 
         std::unique_ptr<SimpleFeature> feature((*factory_)());
-        if (!ParseFeature(static_cast<const base::DictionaryValue*>(*list_iter),
-                          iter.key(),
-                          feature.get()))
+        if (!ParseFeature(dict, iter.key(), feature.get()))
           continue;
 
         features->push_back(std::move(feature));
       }
 
       std::unique_ptr<ComplexFeature> feature(
           new ComplexFeature(std::move(features)));
       feature->set_name(iter.key());
 
       features_[iter.key()] = std::move(feature);
@@ skipping 47 matching lines @@
   std::vector<Feature*> result;
   result.reserve(std::distance(first_child, after_children));
   for (FeatureMap::const_iterator it = first_child; it != after_children;
        ++it) {
     result.push_back(it->second.get());
   }
   return result;
 }
 
 }  // namespace extensions