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

chrome/browser/banners/app_banner_settings_helper.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 "chrome/browser/banners/app_banner_settings_helper.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <string>
@@ skipping 316 matching lines @@
 
   base::ListValue* could_show_list = nullptr;
   if (!app_dict->GetList(event_key, &could_show_list)) {
     could_show_list = new base::ListValue();
     app_dict->Set(event_key, base::WrapUnique(could_show_list));
   }
 
   // Trim any items that are older than we should care about. For comparisons
   // the times are converted to local dates.
   base::Time date = BucketTimeToResolution(time, gMinimumMinutesBetweenVisits);
-  base::ValueVector::iterator it = could_show_list->begin();
-  while (it != could_show_list->end()) {
+  for (auto it = could_show_list->begin(); it != could_show_list->end();) {
     if ((*it)->IsType(base::Value::TYPE_DICTIONARY)) {
       base::DictionaryValue* internal_value;
       double internal_date;
       (*it)->GetAsDictionary(&internal_value);
 
       if (internal_value->GetDouble(kBannerTimeKey, &internal_date)) {
         base::Time other_date =
             BucketTimeToResolution(base::Time::FromInternalValue(internal_date),
                                    gMinimumMinutesBetweenVisits);
         if (other_date == date) {
@@ skipping 120 matching lines @@
   base::DictionaryValue* app_dict =
       GetAppDict(origin_dict.get(), package_name_or_start_url);
   if (!app_dict)
     return result;
 
   std::string event_key(kBannerEventKeys[APP_BANNER_EVENT_COULD_SHOW]);
   base::ListValue* could_show_list = nullptr;
   if (!app_dict->GetList(event_key, &could_show_list))
     return result;
 
-  for (auto value : *could_show_list) {
+  for (const auto& value : *could_show_list) {
     if (value->IsType(base::Value::TYPE_DICTIONARY)) {
       base::DictionaryValue* internal_value;
       double internal_date = 0;
       value->GetAsDictionary(&internal_value);
       double engagement = 0;
 
       if (internal_value->GetDouble(kBannerTimeKey, &internal_date) &&
           internal_value->GetDouble(kBannerEngagementKey, &engagement)) {
         base::Time date = base::Time::FromInternalValue(internal_date);
         result.push_back({date, engagement});
@@ skipping 122 matching lines @@
   // must only be active when there is one singular group under the banner
   // experiment, otherwise the banner and site engagement banner experiments
   // will conflict.
   //
   // Making the experiment active when a variations key is present allows us
   // to have experiments which enable multiple features under site engagement.
   std::string param = variations::GetVariationParamValue(
       SiteEngagementService::kEngagementParams, kBannerSiteEngagementParamsKey);
   return !param.empty();
 }