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

chrome/browser/permissions/chooser_context_base.cc

 // Copyright 2015 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 "chrome/browser/permissions/chooser_context_base.h"
 
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
@@ skipping 37 matching lines @@
       GetWebsiteSetting(requesting_origin, embedding_origin);
   std::unique_ptr<base::Value> objects;
   if (!setting->Remove(kObjectListKey, &objects))
     return results;
 
   std::unique_ptr<base::ListValue> object_list =
       base::ListValue::From(std::move(objects));
   if (!object_list)
     return results;
 
-  for (base::ListValue::iterator it = object_list->begin();
-       it != object_list->end(); ++it) {
+  for (auto& object : *object_list) {
     // Steal ownership of |object| from |object_list|.
-    std::unique_ptr<base::Value> object(*it);
-    *it = nullptr;
-
     std::unique_ptr<base::DictionaryValue> object_dict =
         base::DictionaryValue::From(std::move(object));
     if (object_dict && IsValidObject(*object_dict))
       results.push_back(std::move(object_dict));
   }
   return results;
 }
 
 std::vector<std::unique_ptr<ChooserContextBase::Object>>
 ChooserContextBase::GetAllGrantedObjects() {
   ContentSettingsForOneType content_settings;
   host_content_settings_map_->GetSettingsForOneType(
       data_content_settings_type_, std::string(), &content_settings);
 
   std::vector<std::unique_ptr<Object>> results;
   for (const ContentSettingPatternSource& content_setting : content_settings) {
     GURL requesting_origin(content_setting.primary_pattern.ToString());
     GURL embedding_origin(content_setting.secondary_pattern.ToString());
     if (!requesting_origin.is_valid() || !embedding_origin.is_valid())
       continue;
 
     std::unique_ptr<base::DictionaryValue> setting =
         GetWebsiteSetting(requesting_origin, embedding_origin);
     base::ListValue* object_list;
     if (!setting->GetList(kObjectListKey, &object_list))
       continue;
 
-    for (base::Value* object : *object_list) {
+    for (const auto& object : *object_list) {
       base::DictionaryValue* object_dict;
       if (!object->GetAsDictionary(&object_dict) ||
           !IsValidObject(*object_dict)) {
         continue;
       }
 
       results.push_back(base::WrapUnique(
           new Object(requesting_origin, embedding_origin, object_dict,
                      content_setting.source, content_setting.incognito)));
     }
@@ skipping 50 matching lines @@
   return value;
 }
 
 void ChooserContextBase::SetWebsiteSetting(const GURL& requesting_origin,
                                            const GURL& embedding_origin,
                                            std::unique_ptr<base::Value> value) {
   host_content_settings_map_->SetWebsiteSettingDefaultScope(
       requesting_origin, embedding_origin, data_content_settings_type_,
       std::string(), value.release());
 }